'Fridericus II' was the German companion offensive to 'Wilhelm' and a logical successor to 'Fridericus I', undertaken by Generaloberst Ewald von Kleist’s 1^st Panzerarmee and part of Generaloberst Friedrich Paulus’s 6^th Army as a preliminary to the German campaign of summer 1942 to clear General Major Fyedor M. Kharitonov’s 9^th Army and General Major Kirill S. Moskalenko’s 38^th Army of General Leytenant Fyedor Ya. Kostenko’s South-West Front from the area of Kupyansk, in the course of the offensive securing a bridgehead over the Oskol river (22/26 June 1942).

'Wilhelm' was intended to trap General Leytenant Nikolai N. Nikishin’s 28^th Army in what was left of the Volchansk salient, and thus provide cover on the south of the main thrust of Paulus’s 6^th Army in 'Blau I', in which it was to drive initially to the north-east from the area of Belgorod. The tasks envisaged for 'Fridericus II' were the encirclement of the Soviet 9^th Army and 38^th Army to the north and east of Izyum and advance the 1^st Panzerarmee's front some 30 miles (48 km) to the east to reach its starting point for 'Blau II' on the Oskol river in the area below Kupyansk.

The key formation in each of these operations was General Eberhard von Mackensen’s III Panzerkorps, as the III Corps (mot.) had been redesignated on 21 June, the eve of the offensive. In May, the attack of this corps across the mouth of the Izyum bulge had brought it north from Generaloberst Ewald von Kleist’s Armeegruppe 'von Kleist' (centred on von Kleist’s own 1^st Panzerarmee) into the sector of the 6^th Army. For 'Wilhelm', the corps was attached to the 6^th Army and was to strike to the north-east along the Burluk river as the southern arm of the planned envelopment, and for 'Fridericus II' it was to revert to von Kleist’s 1^st Panzerarmee, the wheel 90° to the right, and drive just to the east of south, past Kupyansk, in order to complete the second encirclement from the north and bring itself into position for 'Blau II'.

On the Soviet side, Marshal Sovetskogo Soyuza Semyon K. Timoshenko, commander of the South-West Direction and South-West Front, together with General Major Nikita S. Khrushchev and General Leytenant Hovhannes Kh. Bagramyan, Timoshenko’s political commissar and chief-of-staff respectively, could not be ignorant of the fact that they faced further strategic and operational problems in the aftermath of the failure of the 'Izyum Bridgehead Offensive Operation', but not their magnitude or their possible solutions, if any. On 29 May, the three leaders sent to the Stavka an appraisal of the situation, in which they said that they expected renewed German attacks in five to 10 days. However, Timoshenko and his direction and front staffs believed, as apparently did the Stavka and the general staff, that the Germans were about to renew their grand strategic effort to take Moscow, and therefore that anything which might occur in the south was of only secondary significance. Nevertheless, Timoshenko appreciated that his fronts and armies were in urgent need of reinforcement and, unwilling at this time himself to face Iosif Stalin, despatched Khrushchev and Bagramyan to go to the Soviet leader and request reinforcements. Khrushchev and Bagramyan found Stalin less reproachful than they had expected in the aftermath of the failure of the 'Izyum Bridgehead Offensive Operation' and the following German success of 'Fridericus I'. Bagramyan knew that one of Stalin’s outstanding characteristics as a wartime leader was his iron self-control. And Timoshenko’s subordinates were in fact given reinforcements, though not on any lavish scale: seven infantry divisions, two tank corps and four tank brigades.

For both 'Wilhelm' and 'Fridericus II', the Germans knew that speed was of the essence. Each of these envelopments was to be shallow and therefore not very difficult for the Soviets to escape, and the wet conditions of May had kept the roads muddy. The first five days of June were dry and not, but on 6 June the sky was overcast, which dropped the temperature quite acutely and was accompanied by intermittent rain squalls. Because of the rain, the III Panzerkorps reported that its tanks would have hard going on level ground and might get stuck on inclines, while General Kurt Pflugbeil’s IV Fliegerkorps of Generaloberst Alexander Löhr’s Luftflotte IV found itself with a problem as its landing strips became too soft for loaded Junkers Ju 87 dive-bombers to take off. The 6^th Army, which had been ready to launch 'Wilhelm' on 7 June, therefore ordered a one-day delay. While the 6^th Army waited one day and then another for the ground to become firm enough for the commitment of 'Wilhelm', farther to the south in 'Störfang', Generaloberst Erich von Manstein’s 11^th Army was fighting its way into the northern part of Sevastopol’s perimeter much more slowly than it had anticipated in the steadily more bloody campaign to complete the German seizure of western Crimea.

'Wilhelm' finally began on 10 June, and for Generalfeldmarschall Fedor von Bock, commander of Heeresgruppe 'Süd', the results of the first day’s fighting were highly satisfying. Despite occasional bursts of rain, the III Panzerkorps surged across the Burluk river after capturing two bridges, and began its advance upstream. To the north of Volchansk, General Walter Heitz’s VIII Corps fared even better, for it took three bridges over the Donets river and was passing to the north-east of Volchansk by a time late in afternoon of the same day. During the night of 10 June, von Bock had travelled by train from his headquarters at Poltava to Kharkov in order to be with the III Panzerkorps on the following day. The army group commander reached the front early in the afternoon just in time to see a downpour of rain which in less than one hour engulfed the tanks in mud. The VIII Corps, which was in essence and infantry formation, was able to keep moving in these coinditions and reached Belyy Kolodez, 10 miles (16 km) to the south-east of Volchansk, at a time late in the afternoon. The armour was to have been there to meet the infantry, but was still 30 miles 48 km) distant on the Burluk river.

Arriving back at the headquarters of the 6^th Army after the fall of night, von Bock learned what Paulus had already known for some hours, namely that the 28^th Army had abandoned its front to the west of the Donets river and was retiring to the east. Throughout 12 June, the III Panzerkorps, spurred by von Bock and Paulus to forget all but the completion of the encirclement, ground its way to the north even as the columns of Soviet troops headed to the south-east past Bely Kolodez and thus escaped the pocket which was slowly coming into existence. Finally, before it made the contact with the leading elements of the VIII Corps during the morning of 13 June, the III Panzerkorps had to fight through several lines of Soviet tanks which had been emplaced to hold open the jaws of the German pincer movement to the south-east of Bely Kolodez. Once the jaws had closed, the mopping-up process was completed quickly and netted 24,800 prisoners.

While 'Wilhelm' was not quite living up to expectations, von Bock was becoming increasingly unhappy with the slow progress of 'Störfang', for he had reckoned on having air units from the Sevastopol front in time for use in 'Blau I', otherwise 'Braunschweig', on 20 June, and he appreciated the operation and tactical futility of keeping the troops for the main operation standing idly beside their loaded vehicles with nothing to do. On 13 June von Bock gave consideration to the launch of 'Blau I' without the support of warplanes brought north from Crimea, but soon decided that this was impractical. While Adolf Hitler was currently on holiday in Bavaria and had not shown any recent interest in 'Fridericus II' and 'Blau I', the Oberkommando des Heeres did share von Bock’s concerns about the loss of invaluable time. Late in the night of 14 June, the Oberkommando des Heeres forwarded to von Bock Hitler’s order for the execution of 'Fridericus II' and the launch of 'Blau I' as soon as the Luftwaffe could provide the necessary air support. The earliest day for the launch of 'Blau I' was thus 23 June.

The start of 'Fridericus II' was scheduled for 17 June, but daily rain storms meant that the preparations could not been completed until 20 June, and the operation therefore began only on 22 June. Yet again, the primary German formation was the III Panzerkorps, which was to attack to the east from the area of Chuguyev to the south-east in the direction of Kupyansk and then to turn almost directly to the south along the Oskol river. In the south, General Maximilian de Angelis’s XLIV Corps was to cross the Donets river in the area between Izyum and the mouth of the Oskol river and drive just to the east of north to meet the III Panzerkorps in the vicinity of Gorokhovatka. Elements of General Walter von Seydlitz-Kurzbach’s LI Corps were to operate between the III Panzerkorps and the LXIV Corps, and others of this corps' elements in the area to the north of the III Panzerkorps.

Pushing forward in rain, the III Panzerkorps advanced half of the way to Kupyansk on the first day and began to turn three divisions, with Generalmajor Wilhelm von Apell’s 22^nd Panzerdivision in the lead, toward the south. The XLIV Corps seized a bridgehead over the Donets river. During the morning of the following day, however, all along the front between Kupyansk in the north and Izyum in the south, Soviet units were on the march to the east in the direction of the Oskol river. Overrunning some of these retreating units, Generalleutnant Hans-Valentin Hube’s 16^th Panzerdivision entered the north-western part of Kupyansk by the fall of night. Late in the afternoon of 24 June, as it drove to the south, the 22^nd Panzerdivision met the leading elements of Generalleutnant Erich Diestel’s 101^st leichte Division advancing to the north, at Gorokhovatka on the Oskol river to the north-east of Izyum, and 'Fridericus II' had been completed.

By 26 June the Germans had cleared the last pockets of Soviet troops, and the 1^st Panzerarmee's bag of prisoners in 'Fridericus II' reached 22,800 men.

While both von Bock and von Kleist expressed their complete satisfaction with the completion of the two undertakings, there were mixed reactions at higher command levels as the battles had been comparatively easy but yet had netted comparatively few prisoners. In conversation with Generaloberst Franz Halder, the chief of the Oberkommando des Heeres general staff, von Bock said that it might be waiting for the USA to intervene on a major scale now that the Americans had been involved in the war for more than six months and had therefore decided, until that time came, to avoid vulnerability to major defeats.

The operations completed the virtual destruction of the South-West Front as an effective formation.