'Rösselsprung' (ii) was a German combined airborne and ground assault by General Ernst von Leyser’s XV Gebirgskorps on the headquarters of the Yugoslav partisan movement outside Drvar in the western part of the puppet state of Croatia with the object of capturing or killing Marshal Josip Broz Tito and his staff, and of destroying support facilities and the co-located Allied military missions (25 May/6 June 1944).

'Rösselsprung' (ii) became known to the Yugoslav resistance movement as the 'Seventh Enemy Offensive', and was conceived as a coup-de-main undertaking based on a parachute and gliderborne assault by SS-Hauptsturmführer Kurt Rybka’s 500^th SS Fallschirmjägerbataillon, which was to be relieved by ground force elements of the XV Gebirgskorps converging on Drvar.

At this time the partisan headquarters was located in the hills near Drvar, and also in this location were the Allied powers' two most senior representatives, Randolph Churchill and Evelyn Waugh. In the event Tito, his principal headquarters staff and the Allied military personnel escaped, despite their presence in Drvar at the time of the airborne assault, which failed as a result of a number of factors, including partisan resistance in the town itself and along the approaches to Drvar, very bad German security, the failure of the various German intelligence agencies to share the limited intelligence available on Tito’s exact location, and the absence of any contingency planning by the commander of the airborne force.

The background to 'Rösselsprung' (ii) can be found in 1943, when two Axis offensives ('Weiss' [ii] and 'Schwarz' [ii]) during the first half of the year set back the partisan cause to a notable degree, but in September of the same year Tito was able to take advantage of Italy’s armistice with the Allies to increase the area of Yugoslavia under partisan control and also to double the size of his forces to about 200,000 men, many of them armed with captured Italian weapons. Late in November, Tito held a national congress at Jajce in the liberated area of north-western Yugoslavia and designated himself as marshal and prime minister. Tito established his headquarters at nearby Drvar in the Dinaric Alps, and temporarily suspended his usual practice of moving constantly to prevent attempts to trap and seize him.

Drvar was located within the puppet state of Croatia, and Tito’s headquarters was initially located in a cave about 1,100 yards (1000 m) to the north of the centre of Drvar. The Unac river runs along the base of the ridge line above the cave, creating an obstacle to movement between the town and the cave, and a railway line ran along the ridge line behind the cave. As well as the partisan headquarters, several Partisan and Communist Party of Yugoslavia support, training and youth organisations were also based in and around Drvar at the time, along with the Tito Escort Battalion responsible for his personal safety. The British and Soviet military missions to the partisans were also located in villages close to Drvar, as were some US military officers on various missions. The British mission was headed by Brigadier Fitzroy Maclean, who was in London at the time of the raid, and included Major Randolph Churchill, son of Winston Churchill, and at the time the British mission was led by its second in command, Lieutenant Colonel Vivian Street.

Apart from partisan headquarters and related organisations in and around Drvar, there were between 12,000 and 16,000 partisans in the area to be assaulted by the XV Gebirgskorps. Close to Drvar was General-lajtnant Koča Popović's I Proletarian Corps with the high-grade 1^st Proletarian Division and 6^th 'Lika' Proletarian Division. The headquarters of this corps was sited in the village of Mokronoge, 3.7 miles (6 km) to the east of Drvar, the 6^th Lika Proletarian Division was to the west of Drvar, and the 1^st Proletarian Division was deployed in the area around Jajce and Mrkonjić Grad, some 37 miles (50 km) to the east of Drvar. The large partisan unit closest to Drvar was the 3^rd 'Lika' Proletarian Brigade of the 6^th 'Lika' Proletarian Division, which was based in the villages of Resanovci and Trubar some 6.25 miles (10 km) to the south and south-west of Drvar respectively.

In the wider area of operations were General-lajtnant Slavko Rodić's V Partisan Corps and General-lajtnant Vlado Ćetković's VIII Partisan Corps: the former was deployed to the north-east and north-west of Drvar with its headquarters to the south of the road linking Mrkonjić Grad and Ključ, and the latter was positioned to the south-east with its headquarters in the mountains between the Glamoč and Livno river valleys. Importantly for the forthcoming battle, the 4^th 'Krajina' Division of the V Partisan Corps was deployed between Bihać and Bosanski Petrovac: two of this division’s brigades and one of the 39^th 'Krajina' Division’s brigades formed a defensive arc to the north of Drvar, extending from Bihać through Krupa to Sanski Most. The 9^th 'Dalmatia' Division of the VIII Partisan Corps was deployed to the south between Livno and Bosansko Grahovo.

Three German organisations tried to establish the exact location of Tito’s headquarters and the disposition of the partisan forces in and around Drvar. The first of these was the Benesch Special Unit/Section II of the Abwehr (German armed forces' intelligence service), some of whose members had been involved in identifying Tito’s presence in the town of Jajce before the German offensive to retake that town. The Benesch Special Unit was part of Generalleutnant Friedrich Kühlwein’s Division 'Brandenburg' and comprised ethnic Germans who spoke local languages. The unit had many contacts with both the Četniks and the Ustase militia, and had been tracking Tito since October 1943. The officer responsible for locating Tito before the recapture of Jajce had been Leutnant Kirchner, who had now established a patrol base near Bosansko Grahovo. Kirchner got very close to the Drvar cave, and located the Allied military missions, but despite German radio intercepts confirming that Drvar was the site of Tito’s headquarters, Kirchner was unable to pinpoint the cave as the location of the headquarters. Kirchner was attached to the 500^th SS-Fallschirmjägerbataillon.

The second intelligence organisation was the 216^th Front Reconnaissance Troop of the Abwehr’s Section I. Led by Leutnant Zavadil, the 216^th Front Reconnaissance Troop was also attached to the 500^th SS-Fallschirmjägerbataillon, but contributed little to the intelligence used to plan the raid.

On the orders of Adolf Hitler, SS-Sturmbannführer Otto Skorzeny of the Sicherheitsdienst intelligence branch of the SS, who had commanded the 'Eiche' operation to rescue Mussolini in September 1943, was independently involved in intelligence-gathering during the development of 'Rösselsprung' (ii). After he had obtained information from a partisan deserter, which pinpointed Tito’s headquarters at the cave, Skorzeny proposed a plan to infiltrate Drvar with a small group of soldiers to assassinate the Yugoslav partisan leader. Skorzeny soon discovered that the plan to eliminate Tito had been compromised by poor security in Zagreb, and had nothing further to do with the operation. It seems that he did not pass the intelligence he had gathered to Rybka, commander of the 500^th SS-Fallschirmjägerbataillon and the planner of of the all-important airborne element of the operation.

As a result largely of inter-service rivalry and competition, the three organisations did not share the intelligence they gathered, which had a significant and deleterious effect on the tactical planning and execution of the operation.

The partisan movement had its own intelligence network, and this was very effective. The partisans had been aware for some time of the presence of the 500^th SS-Fallschirmjägerbataillon in Yugoslavia, and the general threat of an airborne assault for more than six months. The partisans may also have become aware of the segregation of the 500^th SS-Fallschirmjägerbataillon and/or the concentration of transport aircraft and gliders at Zagreb and Banja Luka more than one month before the operation, and had also managed to recapture the deserter Skorzeny had interrogated. As a result of these early indicators of an attack, Tito’s main headquarters had been relocated to another cave near the village of Bastasi, 4.3 miles (7 km) to the west of Drvar, Tito then used the Drvar cave during the day and that at Bastasi at night. In addition to this precaution, elements of the 6^th 'Lika' Proletarian Division were moved closer to Drvar.

On 23 May, a Fieseler Fi 156 Storch battlefield reconnaissance aeroplane flew a number of parallel runs up and down the Una river valley over Drvar at an altitude of about 1,970 ft (600 m), which was clear evidence that aerial photography was being undertaken. The aeroplane paid particular attention to the villages of Prinavor and Trninić Brijeg, where the British military mission and US military personnel were located. This flight was observed by Street, the acting commander of the British mission, who assumed it was spotting for a bombing raid and advised both Tito and the Americans. Both Allied missions therefore moved their locations.

Despite the intelligence they had received and the observations made by the British, the partisans seem to have been largely unconcerned about the threat, and Tito’s chief-of-staff, General-pukovnik Arso Jovanović, stating that a German attack was impossible. The most obvious indicator that Tito himself was unaware of the imminent attack is that he remained at the Drvar cave overnight on the evening of 24 May, after his birthday celebrations, instead of returning to Bastasi.

Through 'Ultra' intercepts and decrypts of German signals traffic, the British had become aware that the Germans were planning an operation codenamed 'Rösselsprung' (ii), but the information available did not include the location or objective of the operation.

Higher-level planning for 'Rösselsprung' (ii) started on 6 May after the receipt of orders from Generalfeldmarschall Maximilian Reichsfreiherr von Weichs, commander of Heeresgruppe 'F', and Hitler approved von Weichs’s final plans on 21 May. The order to von Leyser’s XV Gebirgskorps was issued by Generaloberst Dr Lothar Rendulic, commander of the 2^nd Panzerarmee, on the same day, leaving only three days for preparation. Headquartered at Knin, von Leyser was responsible for the tactical conduct of the operation. The XV Gebirgskorps was greatly strengthened from the reserves of Heeresgruppe 'F', the 2^nd Panzerarmee and SS-Obergruppenführer und General der Waffen-SS Arthur Phleps’s V SS Gebirgskorps. These reinforcements included two Panzer companies, the reconnaissance battalions of Generalleutnant Walter Stettner Ritter von Grabenhofen’s 1^st Gebirgsdivision (the 54^th Gebirgsaufklärungsabteilung) and Generalleutnant Fritz Neidholdt’s 369^th Division (kroatisch), and most of SS-Brigadeführer und Generalmajor der Waffen-SS Karl Reichsritter von Oberkamp’s 7^th SS Freiwilligen Gebirgsdivision 'Prinz Eugen'.

In its basic form, the plan developed by the XV Gebirgskorps was for Luftwaffe warplanes to undertake a heavy bombing attack on the partisan positions in and around Drvar, and then for the 500^th SS-Fallschirmjägerbataillon to make the 'Schneegestöber' (i) parachute and gliderborne assault to capture or kill Tito and to destroy his headquarters, and also to capture or destroy the Allied military missions. On the same day, ground elements of the XV Gebirgskorps were to converge on Drvar to link with the 500^th SS-Fallschirmjägerbataillon. A small reconnaissance aeroplane was to fly into Drvar after its capture to retrieve Tito or his body.

Rybka received an outline of the operation on 20 May, and more details on the next day. Appreciating that the transport aircraft and glider strength available would not be adequate for the delivery of the 500^th SS-Fallschirmjägerbataillon in a single lift, Rybka decided on a plan involving two waves. The first wave of 654 men was to undertake the initial assault at 07.00 and the second wave of 220 reinforcement troops was to follow about five hours later. Critically, the intelligence Rybka was given regarding the suspected location of Tito’s headquarters was that it was in or near a cemetery on high ground to the south-west of Drvar’s centre, but this was nearly 1.25 miles (2 km) from the actual headquarters cave.

Rybka’s plan for the first wave called for the delivery of 314 paratroopers in three groups (Gruppe 'Rot', Gruppe 'Grün' and Gruppe 'Blau') to secure the town, and another 354 men in six gliderborne assault groups to carry out specific tasks. Thus the 110 men of the Gruppe 'Panther' were to take Tito’s headquarters after landing at the cemetery, the 40 men of the Gruppe 'Greifer' to destroy the British military mission in the village of Prnjavor some 1.25 miles (2 km) to the south of Drvar on the road to Bosansko Grahovo, the 50 men of the Gruppe 'Stürmer' to destroy the Soviet military mission between the centre of Drvar and the Unac river, the 50 men of the Gruppe 'Brecher' to destroy the US military mission in the village of Trninić Brijeg 1.25 miles (2 km) to the south of Drvar’s centre, the 70 men (including men of the Division 'Brandenburg', the Abwehr men of the Sonderkommando 'Zavadil' and some Četniks) of the Gruppe 'Draufgänger' to take and hold the crossroads immediately to the west of Drvar and a nearby site suspected of being a communications facility, and the 20 men of the Gruppe 'Beisser' to seize an outpost radio station to the south of Prnjavor and then support the Gruppe 'Greifer'. The second wave of 220 men based on the training company of the 500^th SS-Fallschirmjägerbataillon were to arrive by parachute at 12.00.

It seems that Rybka did not take into consideration significant contingencies such as errors in the intelligence on the location of Tito’s headquarters, and his only contingency plan was the firing of a red signal flare to order all available forces to converge on his position for subsequent tasks.

On 22 May, the 500^th SS-Fallschirmjägerbataillon was moved airfields at Nagy-Betskerek, Zagreb and Banja Luka, but the men were not briefed on the operation until a few hours before its start. They then entered their transport aircraft and 10-man gliders which would deliver them.

The ground force’s plan for the XV Gebirgskorps took the form of nine separate but co-ordinated thrusts toward the area of Drvar an Bosanski Petrovac area from all directions.

The 384^th Grenadierregiment of Generalleutnant Eduard Aldrian’s 373^rd Division (kroatische) and part of the 2^nd Kompanie of the 202^nd Panzerabteilung were Oberst Willam’s Kampfgruppe 'Willam', which was to advance to the east from 05.00 from the village of Srb toward Drvar, had the primary responsibility for relieving and then taking command of the 500^th SS-Fallschirmjägerbataillon in Drvar on 25 May, and was then to attack in the direction of Bosanski Petrovac.

One battalion group of the 373^rd Division (kroatische) was to depart Lapac at 05.00 and head to the east through Kulen Vakuf to capture the crossroads at Vrtoče and then, should this prove necessary, advance to the north-west in the direction of Bihać to open the road.

The 92^nd Grenadierregiment (mot.), with the 54^th Gebirgsaufklärungsabteilung of von Grabenhofen’s 1^st Gebirgsdivision, the 55^th Pionierbataillon of Generalleutnant Helmuth von Pannwitz’s 1^st Kosaken-Kavalleriedivision, the 468^th Panzerspähkompanie zbV and a regimental group of the Croat 2^nd Jägerbrigade was to advance to the south-east from Bihać and Bosanska Krupa at 05.00 through the village of Vrtoče to capture Bosanski Petrovac as quickly as possible, destroy the partisans located there, and seize the partisan airfield and supply installations. After Bosanski Petrovac had been taken, elements of this force were to be sent toward Drvar to prevent the withdrawal of partisans along that road and to link with the 500^th SS-Fallschirmjägerbataillon in Drvar.

One regimental group of von Oberkamp’s 7^th SS Gebirgsdivision 'Prinz Eugen' was to advance to the west from the area of Mrkonjić Grad, break through any partisan resistance in the area to the east of the Sana river and then advance on a wide front to block partisan escape routes out of Drvar to the east. Part of this group was to advance from Jajce along the line of the railway and the roads through Savici to reach their objective, the area around Mliniste power station.

The extemporised Kampfgruppe 'Panzergrenadier Sturmbataillon' of officer cadets and the 1^st Kompanie/202^nd Panzerabteilung, under the command of the 7^th SS Gebirgsdivision, was to advance from Banja Luka toward Ključ to seize the crossing point across the Sana river used by the partisans.

The 105^th SS Aufklärungsabteilung, strengthened by a Panzer company, was to advance from Livno and occupy any partisan supply installations in the Livno river valley, and prevent any partisan withdrawal to the south of Drvar by attacking through Bosanski Grahovo toward Drvar.

The reinforced 369^th Aufklärungsabteilung of Generalleutnant Emil Zellner’s 373^rd Division (kroatische), under command of the 105^th SS Aufklärungsabteilung, was to advance from Livno up the Glamoč river valley against any partisan forces withdrawing from Drvar to the south-east.

The 1^st Regiment 'Brandenburg' of the Division 'Brandenburg', together with the 501^st and 502^nd Dinarski Četnik Corps, were to advance from Knin toward Bosanski Grahovo and conduct special operations against the partisans in the area of Prekaja and Drvar area.

The offensive began with the advance of ground forces from their assembly areas around the planned operational area. Then, at about 06.35, five squadrons of Luftwaffe bombers, including Junkers Ju 87 dive-bombers, started to attack targets in Drvar and Bosanski Petrovac as the first of an eventual 440 sorties flown on 25 May.

The 500^th SS-Fallschirmjägerbataillon began to drop and glide onto its objectives at 07.00, most of the paratroopers and glider pilots being able to land relatively close to their targets despite the smoke and dust raised by the bombing. Some gliders landed significantly off course, including one which landed in front of the Bastasi cave 4.3 miles (7 km) to the west of Drvar, and several which landed near Vrtoče in the area of Drvar (not to be confused with Vrtoče between Bihać and Petrovac on the axis of the 92^nd Grenadierregiment (mot.). The men in the glider which landed in Bastasi were immediately killed by members of the Tito Escort Battalion guarding the cave, and the occupants of the gliders at Vrtoče had to fight their way toward Drvar. After landing, the first wave of the 500^th SS-Fallschirmjägerbataillon quickly gained control of Drvar.

The Gruppe 'Panther', supported by the Gruppe 'Rot', overcame minimal resistance at the cemetery, and Rybka established his headquarters behind the cemetery walls. However, there was no sign of Tito or his headquarters. The Gruppe 'Greifer' and Gruppe 'Brecher' were also unsuccessful as the British and US missions had relocated following the warning provided by the German aerial reconnaissance of 23 May. Parts of the Gruppe 'Stürmer' landed their gliders in a field immediately to the south of the Drvar cave and came under fire from members of the Tito Escort Battalion on the high ground in the area of the cave. The Gruppe 'Draufgänger' landed in its gliders at the designated crossroads, then assaulted a building it believed was the partisan communications centre: the building was in fact the office of the Central Committee of the Communist Party of Yugoslavia, whose personnel put up a sterling defence until the building was levelled with explosives. The paratroopers of the Gruppe 'Blau' and Gruppe 'Grün' came down in the eastern part of Drvar, where most of the population lived, and also became engaged in heavy fighting. The Young Communist League of Yugoslavia had just finished a conference in Drvar, and many of the delegates were still in the town, took up whatever weapons they could, and began to fight the paratroopers attempting to establish a cordon on the eastern side of the town.

About 1.25 miles (2 km) farther to the east, on the road to Mokronoge, was the partisan Officer School with about 130 students. As soon as they heard the sounds of battle, the students headed to the west with a few rifles and pistols. The students divided into two groups: the smaller of these crossed the Unac river and advanced to the west along the railway line on the ridge leading toward Tito’s cave, and the larger collected arms and ammunition from several German parachute canisters which had gone astray, then fell on the Gruppe 'Grün' and Gruppe 'Blau' from the east at about 08.00, suffering severe casualties but nonetheless maintaining continuous pressure on the German flank. By about 09.00, the Germans had largely secured Drvar and the available troops, armed with photographs of Tito, then began a house-to-house search and questioned all the civilians they could find. Soon after this, Rybka realised that the partisan resistance was concentrated to the north in the vicinity of the cave, and fired the red signal flare to rally his troops for an assault in that direction.

At about 10.30, Rybka launched a frontal attack across the Unac river with the support of at least one medium machine gun firing into the mouth of the cave. The Germans reached the base of the hill, 165 ft (50 m) from the cave, but suffered severe casualties in the assault and were now beginning to suffer from thirst. Before this attack, Tito and around 20 members of his staff had taken refuge in the cave.

While Rybka was marshalling his men for this attack, partisans from the surrounding area were rushed toward Drvar. Three battalions of the 3^rd 'Lika' Proletarian Brigade of the 6^th 'Lika' Proletarian Division approached from the south-east: of these battalions, one attacked the German position at the cemetery while the other two swung around to strike the Germans from the west.

At about 11.15, after Rybka’s first attack had been beaten, Tito and the small group gathered with him escaped from the cave. There was a platform at the mouth of the cave, and they climbed down a rope through a trapdoor in the platform, although the hysteria of Tito’s mistress Davorjanka Paunović caused some delays. The party split up and, following a stream leading to the Unac river, the small groups climbed the heights to the east and withdrew toward the village of Potoci.

At about 12.00, the second wave of German paratroopers dropped in two groups to the west of the cemetery, but the drop zone lay within the fields of fire of the partisans to the west of Drvar and the newly arrived paratroopers suffered many casualties. Collecting the remainder, Rybka mounted a second attack, but the pressure on his flanks was too heavy and this second assault also failed. Fighting continued throughout the afternoon, each sides suffering heavy losses.

Late in the afternoon, Rybka ordered his force to withdraw to the area of the cemetery and establish a defensive perimeter. During the withdrawal, at least one group of men was cut off and killed. At about 18.00 Rybka was wounded by a grenade blast and was later evacuated with other casualties in the light aeroplane intended to carry away Tito after his capture. At about this time, Rybka’s partisan counterpart in Drvar, Milan Sijan, commander of the 3^rd 'Lika' Proletarian Brigade, was also wounded. By 21.30 the Germans had consolidated their position in the cemetery, although they were completely surrounded by partisans. During the night, the 3^rd 'Lika' Proletarian Brigade attacked the cemetery with the support of the 1^st Battalion of the 3^rd Brigade of the 9^th 'Dalmatia' Division. At 03.30 on 26 May, the partisans launched their final attack on the cemetery and breached the walls in several places, the paratroopers held on.

Despite the fact that its overall strength was in the region of 185,500 men at a time late in May 1944, the 2^nd Panzerarmee was able to provide only some 16,000 men for 'Rösselsprung' (ii) as a result of its ever-increasing commitments against partisan forces throughout occupied Yugoslavia, in which the Germans had to rely increasingly on special forces and improved tactics.The partisans defended the territory they controlled with significant demolition and mining of roads, and roadblocks were manned by patrols and smaller detachments whose task was to hold off attacking Axis forces until reinforcements arrived. During 'Rösselsprung' (ii), the Germans planned to defeat this tactic by combining strong and fast motorised columns with adequate pioneer support. This combination was especially successful for the column led by the 92^nd Grenadierregiment (mot.). Another German tactical innovation was the employment of five reconnaissance battalions for independent operations deep inside partisan-controlled territory.

Throughout 25 May, the ground forces of the XV Gebirgskorps were unable to advance as quickly as had been planned, for there was unexpected resistance from the partisan I Corps, V Corps and VIII Corps along the various axes of advance, there was poor communication and co-ordination between the various columns, and these columns were also attacked by Allied warplanes throughout the day.

It was at 05.00 on 25 May that the Kampfgruppe 'Willam' began its advance to the east from Srb with the object of covering the 12.5 miles (20 km) to Drvar as quickly as possible. The Kampfgruppe met well-organised resistance from the 2^nd 'Lika' Proletarian Brigade of the 6^th 'Lika' Proletarian Division, and after a day’s combat the Germans had captured Trubar (about one-third of the road distance from Srb to Drvar) but were unable to overcome the defences of the hills to the east of the village. Understanding full well the importance of the Kampfgruppe 'Willam' in the German plan, the commander of the 373^th Division, Aldrian, ordered the battalion group of the division to abandon its advance from Lapac to Martin Brod and move to reinforce the Kampfgruppe 'Willam'. The 6^th 'Lika' Proletarian Division’s remaining unit, the 1^st 'Lika' Proletarian Shock Brigade, was deployed to the north along the Una river. The 2^nd 'Lika' Proletarian Brigade requested assistance from the 1^st 'Lika' Proletarian Shock Brigade, but divisional headquarters instructed it instead to send reinforcements to Drvar. At 21.00, the 3^rd Battalion of the 2^nd 'Lika' Proletarian Brigade launched a successful local counterattack on the vanguard of the Kampfgruppe 'Willam' and cut it off from the main body. Willam then decided to halt the advance and organise the remaining units into an all-round defence. At 22.25, Aldrian ordered Willam to resume the attack, but Willam reported that this was impossible as he had lost contact with his own units.

The Kampfgruppe based on the 92^nd Grenadierregiment (mot.) comprised two groupings, a western column based on the regiment itself and an eastern column based on the 54^th Gebirgsaufklärungsabteilung and 1^st Jäger Regiment of the Croat 2^nd Jäger Brigade. The western column advanced to the south-east from Bihać and met resistance from the 6^th 'Krajina' Brigade of the 4^th 'Krajina' Division. By the end of the day, the western column had reached Vrtoče, half-way between Bihać and Petrovac and, as it was fully motorised, had been able to exploit its mobility to outmanoeuvre the partisans by bypassing their main defensive positions to the west, with the pioneers of the Cossack division playing an important role in keeping the column moving. The eastern column started its advance from Bosanska Krupa, aiming to establish contact with the western column at Vrtoče, and advanced 6.25 miles (10 km) before being checked by the defences of the 8^th 'Krajina' Brigade of the 4^th 'Krajina' Division.

The forces under the command of the 7^th SS Gebirgsdivision were organised into northern, central and southern groupings. The northern column comprised the Kampfgruppe 'Panzergrenadier Sturmbataillon' and included a company of tanks. It moved swiftly to the south-west from its starting point near Banja Luka, and had reached Čađavica at a crossroads half-way between Mrkonjić Grad and Ključ by the evening of 25 May, pushing aside the 16^th 'Krajina' Brigade of the 39^th 'Krajina' Division deployed on the right flank of its axis. The rapid advance meant that the 13^th 'Krajina' Brigade of the 39^th 'Krajina' Division was unable to organise an effective defence. The 39^th 'Krajina' Division then ordered the 13^th 'Krajina' Brigade to block the road from Čađavica to Ključ in order to prevent the loss of Ključ, but only one of the brigade’s battalions managed to reach that position by dawn on 26 May.

The central column consisted of the 7^th SS Gebirgsaufklärungsabteilung (mot.) reinforced with one battery of self-propelled guns, and its task was to strike from Mrkonjić Grad, penetrate deeply into partisans' rear and destroy the headquarters of the partisan V Corps in Ribnik. Despite having only two battalions in the area (the third was facing the Kampfgruppe 'Panzergrenadier Sturmbataillon' at Čađavica), the 13^th Proletarian Brigade managed to check this thrust.

The southern column was based on the 13^th SS Gebirgsjägerregiment, reinforced by the 1/7^th SS Gebirgsartillerieregiment and some Četniks. This column launched its assault from the Jajce area, and had the task of reaching Mlinista, some 12.5 miles (20 km) to the south of Ključ. By 17.20, the 2/13^th SS Gebirgsjägerregiment had taken Sipovo, but could progress no farther in the face of the defence put up by the 1^st Proletarian Brigade.

The assault by the 369^th Aufklärungsabteilung and the 105^th SS Aufklärungsabteilung constituted the pair of columns which attacked to the north from Livno. Supplemented by some 200 men of the 6^th Ustase Brigade, the 369^th Aufklärungsabteilung advanced toward Glamoč, and the 105^th SS Aufklärungsabteilung and one Panzer company drove toward Bosansko Grahovo. By 16.00 on 25 May, the 369^th Aufklärungsabteilung's column had reached the village of Han-Vrbe, some 3.1 miles (5 km) from Bosansko Grahovo, but here came under attack from the 2/3^rd 'Krajina' Brigade and forced to retreat. During its withdrawal, this column attacked by two more battalions of the 3^rd 'Krajina' Brigade and driven back all the way to its start line at Livno with heavy losses. A preliminary German report estimated the losses at 50 men, but the 3^rd 'Krajina' Brigade estimated German losses at 191 dead and wounded. The 105^th SS Aufklärungsabteilung's column overcame the resistance of local partisan units and the 1 and 4/13^th 'Dalmatia' Brigade, and by the end of the day had reached Crni Lug about 12.5 miles (20 km) from Bosansko Grahovo. In the evening, the 13^th 'Dalmatia' Brigade was ordered to move toward Tičevo and Drvar in order to reinforce the partisan forces in that area.

The 1^st Regiment 'Brandenburg' of the Division 'Brandenburg', reinforced by a pioneer company of the 373^rd Division and the Četnik 'Dinara' Division, attacked along the road from Knin to Bosansko Grahovo, drove back the local 'Grahovo-Peulje' Partisan Detachment and by the end of the day had advanced 3.1 miles (5 km) past beyond Strmica.

Escorted by elements of the 3^rd 'Krajina' Brigade, Tito made his way to Potoci, where he was met by a battalion of the 1^st Proletarian Brigade and also the staffs of the Allied military missions. The signals officer of the British mission had brought the only surviving radio. Tito had initially favoured a continued attack on the SS paratroopers, but then reassessed the situation and cancelled further attacks. As the German plan, to encircle the partisan high command in a small area around Drvar with concentric attacks and then destroy it with land forces was now evident, a major reorganisation of the partisan deployments was now required. After German troops were seen in the area of Potoci, Tito and his staff were escorted towards Kupres.

The 2^nd Panzerarmee was keeping a close eye on the progress of 'Rösselsprung' (ii). The report of a special unit, sent into the partisans' rear with the help of disguised Četniks several days earlier, caught Rendulic’s particular attention. According to this report, which was received late on 25 May, Tito was in the area of Potoci, half-way between Drvar and Ribnik. Rendulic now instructed von Oberkamp to create a special company-strength detachment of his 7^th SS Gebirgsdivision to infiltrate its way behind the partisan lines in order to kill Tito and destroy the partisan high command. The detachment was formed on the night of 25/26 May from the 11^th Kompanie of the 13^th SS Gebirgsjägerregiment, a number of pioneers, and a group of specially trained personnel of the Division 'Brandenburg' and, after failing to penetrate into partisan-held territory on the same night, tried once again on the following night.

At about 05.00 on 26 May, a Luftwaffe fighter-bomber force attacked the partisans withdrawing from Drvar, and the western column of the 92^nd Grenadierregiment (mot.)'s Kampfgruppe was ordered to assist the eastern column by detaching a reinforced Panzer company from Vrtoče.

On the morning of 26 May, the German columns advancing from Bihać toward Ključ and from Livno and Knin toward Bosansko Grahovo overcame the partisan units on their axes and continued their advance in the face of declining resistance. The 92^nd Grenadierregiment (mot.)'s advance from Vrtoče took Bosanski Petrovac without a fight at about 08.00, and the regiment then continued its advance on Drvar and relieved the 500^th SS-Fallschirmjägerbataillon at 12.45.The Kampfgruppe 'Willam' had established radio contact with the 500^th SS-Fallschirmjägerbataillon at about 07.00 and reached Drvar via Kamenica at 17.00. The 105^th SS Aufklärungsabteilung reached Bosansko Grahovo at 10.30, and here was joined by the 1^st Regiment 'Brandenburg' of the Division 'Brandenburg' at 16.00. The Kampfgruppe 'Panzergrenadier Sturmbataillon' entered Ključ at 14.15.

In the eastern sector, however, the partisan line of defence was still holding. During 26 and 27 May, the 7^th SS Gebirgsdivision maintained its pressure on the 1^st Proletarian Division in the upper part of the Sana river valley, but failed to break through. By the end of 27 May, the front line had stabilised to the north and south of Ribnik. After the defeat it had suffered the previous day, the 369^th Aufklärungsabteilung's column did not resume its advance toward Glamoč on 26 May.

On this day, the rapidly changing situation and communications difficulties combined to create a degree of confusion on each side. Out of contact with its corps headquarters, the 4^th 'Krajina' Division continued to retain two brigades along the road linking Bihać and Petrovac despite the fact that the 92^nd Grenadierregiment (mot.) had already passed along this route and into their rear. The critically important road linking Petrovac and Ključ to the south was left unguarded, endangering Tito and the partisan high command and they escaped from Drvar.

The XV Gebirgskorps failed to recognise and therefore set itself to exploit these flaws in the partisan deployments. After the relief of the 500^th SS-Fallschirmjägerbataillon, the XV Gebirgskorps ordered the units in the Drvar area to disperse. The 92^nd Grenadierregiment (mot.) and the units under its command were instructed to return to the north and attack the brigades of the 4^th 'Krajina' Division on the Grmeč mountain, with the aim of securing the main supply road from Bihać to Petrovac: codenamed 'Grmeč', this undertaking was scheduled to start on the morning of 27 May. The 373^rd Division with the newly subordinated 1^st Regiment 'Brandenburg' of the Division 'Brandenburg' was ordered to conduct a search-and-destroy operation in the area to the south and south-east of Drvar: codenamed 'Vijenac', this undertaking was scheduled to take place simultaneously with 'Grmeč'. The 9^th 'Dalmatia' Division managed to repulse all attacks on 27 May, pushing the Brandenburgers and Četniks back to Bosansko Grahovo. On the same day the 369^th Aufklärungsabteilung's column again tried to advance on Glamoč, but failed.

Unhappy with the development of the operation to this point, Rendulic cancelled 'Grmeč' and 'Vijenac' during the afternoon of 27 May, and ordered von Leyser to move all of his formations and units back to their start positions for a concentric attack on the area in which it was believed that Tito and headquarters of the I Proletarian Corps and V 'Bosnia' Corps were located. The attack was scheduled to begin on the morning of 28 May. Rendulic also sent the 105^th SS Aufklärungsabteilung to the area of Livno and Glamoč, which had been left exposed by the defeat of the 369^th Aufklärungsabteilung's thrust.

Tito, his staff and escorting partisan troops continued toward Kupres, travelling on foot, by horse and on the wagons of a narrow-gauge logging railway.

During its escape, the British mission was able to use its surviving radio to establish contact with its headquarters and, maintaining contact, could thus call in air attacks on the German formations taking part in 'Rösselsprung' (ii) and also on the Luftwaffe warplanes operating in the skies over Yugoslavia. This offensive included more than 1,000 sorties by Air Vice Marshal W. Elliot’s newly formed Balkan Air Force. 'Flounced' was also launched as a costly ground attack by a combined partisan, British and US force on the German-held Dalmatian island of Brač. The attack was launched from the British-held island of Vis further out in the Adriatic Sea on the night of 1/2 June. Fighting continued late into 3 June 1944 and resulted in the reinforcement of the island by a further 1,900 German troops. The assault force on Brač comprised 13 battalions of the 26^th 'Dalmatia' Division, the British No. 43 (Royal Marines) Commando, one troop of No. 40 (Royal Marines) Commando, and a US mountain company, with one howitzer battery and two mountain batteries providing artillery support. After three days of fighting, the combined forces returned to Vis. The partisans suffered losses of 67 men killed, 308 wounded and 14 missing, and the Allied units suffered 60 men killed, 74 wounded and 20 missing, with the commanding officer, Lieutenant Colonel Jack Churchill, a prisoner in German hands.

After six days evading the Germans, the leader of the Soviet mission, General Leytenant Nikolai V. Korneyev, suggested an air evacuation of Tito and the Soviet mission and this was expanded by Street to include the whole party. After three days of deliberation, Tito agreed on 3 June and Street arranged the evacuation the same night from an RAF-operated airfield near the town of Kupres. Seven Douglas C-47 Skytrain aircraft, one with a Soviet crew and the remainder with US crews, carried Tito and his party, the Allied missions and 118 wounded partisans to Bari in south-eastern Italy. Late on 6 June, Tito was delivered by the British escort destroyer Blackmore to Vis, where he re-established his headquarters and was joined by the Allied missions.

The Soviet foreign minister, Vyacheslav M. Molotov, believed that the British had known more about the attack than they were prepared to admit, this Soviet belief being based on the absence of both Maclean and Churchill from Drvar at the time of the attack. On 28 May, Molotov sent a message to Korneyev detailing his suspicions.

Although Tito’s headquarters, along with several other partisan organisations, had suffered a temporary disruption and some important staff personnel had been lost, all the affected partisan organisations were quickly relocated and began work once more. Drvar had reverted to partisan control within a few weeks of 'Rösselsprung' (ii).

The operation was a failure as Tito, his principal headquarters staff and the Allied military personnel had escaped, despite the fact that they had been in Drvar at the time of the airborne assault. The failure resulted from a number of factors, including partisan resistance in the town itself against the airborne troops and along the approaches to Drvar against the ground troops. The failure of the various German intelligence agencies to share the limited intelligence available on Tito’s exact location was also a contributory factor, and the failure to share intelligence was compounded by a lack of contingency planning by the airborne force’s commander.

The 500^th SS-Fallschirmjägerbataillon was decimated, for it suffered the loss of 576 men killed and 48 wounded: only 200 of the battalion’s men were still fit to fight on the morning of 26 May. The battalion continued throughout the rest of the war as the sole SS parachute unit, although its name was later changed to the 600^th SS-Fallschirmjägerbataillon. 'Rösselsprung' (ii) was the battalion’s only combat parachute operation.

According to a German report, the ground troops of the XV Gebirgskorps lost 213 men killed, 881 wounded, and 51 missing during the operation, and the same report claimed that 6,000 partisans had been killed. According to Kumm, the commander of the 7^th SS Gebirgsdivision, the partisan losses included 1,916 confirmed and another 1,400 estimated killed, and 161 taken prisoner. Kumm also claimed that six Allied aircraft had been shot down during the operation. According to a partisan source, the Yugoslavs' total losses were 399 persons killed, 479 wounded and at least 85 missing. Of this total, the casualties suffered in fighting with the 500^th SS-Fallschirmjägerbataillon at Drvar were 179 persons killed, 63 wounded and 19 missing.