The 'Cottbus-Potsdam Offensive Operation' was one of the last Soviet undertakings on the Eastern Front, and also the third of the five sub-operations together constituting the 'Berlin Strategic Offensive Operation' (16/27 April 1945).

The other four sub-operations were the 'Stettin-Rostock Offensive Operation' (16 April/8 May), the 'Seelow-Berlin Offensive Operation' (16 April/2 May), the 'Spremberg-Torgau Offensive Operation' (19/25 April) and the 'Brandenburg-Rathenow Offensive Operation' (3/8 May).

On 3 April, a directive of the Soviet supreme command ordered Marshal Sovetskogo Soyuza Ivan S. Konev’s 1^st Ukrainian Front firstly to prepare and implement an offensive to defeat the German grouping in the Cottbus area and to the south of Berlin, capture the line between Beelitz and Wittenberg within 10 to 12 days of the operation, to advance farther along the Elbe river to Dresden, to prepare to follow the capture of Berlin with an advance on Leipzig; and secondly to deliver the main blow with five combined-arms armies and two tank armies from the Triebel region in the general direction of Spremberg and Belzig.

Despite the fact that his front was not currently involved in the Soviet overall plan for the seizure of Berlin, Konev decided to incorporate in his offensive the prerequisites for involvement in the battle for the German capital. Fully appreciating the inevitable difficulties of urban combat for armoured and mechanised formations, Konev decided to use the infantry of General Polkovnik Vasili N. Gordov’s 3^rd Guards Army in his planned commitment in the battle for Berlin. In his general directive of 8 April to the troops of his front, Konev ordered the preparation of one infantry division for action as part of a special detachment of the 3^rd Guards Army advancing from Trebbin to Berlin, but Gordov was given more forceful instructions to use his strengthened army to break through the [German] defences on the western bank of the Neisse river in the area of Forst, the intersection of the roads and Autobahn highways 0.6 miles (1 km) to the south-east of Klein Bademeisel, to destroy the opposing [German forces] and, rapidly developing his main offensive to bypass Cottbus from the south, to reach the line line lining Zossen and Nimchek via Belsitz, from which the main forces were to attack Berlin from the south and one corps from the south-west.

Gordov made a slight modification of Konev’s instruction by aiming his offensive’s axis straight through Cottbus. In his decision, he indicated his intention to inflict the main blow by bypassing Cottbus from the south in the direction of Fetschau, Golsen and Luckenwalde in co-operation with General Polkovnik Pavel S. Rybalko’s 3^rd Guards Tank Army and thus to advance his main strength to the line the between Zossen and Beelitz, from which the CXX Corps and LXXVI Corps were to strike at Berlin from the south and the XXI Corps from the south-west.

On 14 April, Konev issued a new order revising the order in which his formations were to be committed. The 3^rd Guards Tank Army was now to cross the Neisse river together with the infantry formations, and then move ahead of the infantry and by the end of the offensive’s first day seize bridgeheads across the Spree river. To speed the advance, the VI Guards Tank Corps was withdrawn from the line between Forst and Cottbus, leaving the assault on these points to the infantry. On the second day of the offensive, the forward detachments of the VI Guards Tank Corps and VII Guards Tank Corps were now to take Düben and Luckau one day earlier than had initially been scheduled.

The decisive role in the Soviet offensive was to be played by Rybalko’s 3^rd Guards Tank Army and General Polkovnik Dmitri D. Lelyushenko’s 4^th Guards Tank Army, while lesser but nonetheless important parts were to be played by Gordov’s 3^rd Guards Army, General Polkovnik Afanasi P. Beloborodov’s 5^th Guards Army and General Polkovnik Nikolai P. Pukhov’s 13^th Army.

The forces of the 1^st Ukrainian Front were opposed by elements of Heeresgruppe 'Mitte', at the head of which Generalfeldmarschall Ferdinand Schörner came to the conclusion that the main goal of the Soviet offensive would be to break through Saxony in order to meet the US forces advancing from the west and thereby cut Germany into northern and southern parts. Thus Schörner concentrated his army group’s large reserves Görlitz. General Kurt Wäger’s V Corps (Generalleutnant Heinrich Nickel’s 342^nd Division, Generalleutnant Harry von Kirchbach’s 214^th Division and Generalleutnant Hans Schmidt’s 275^th Division as well as Kampfgruppen of SS-Standartenführer Rüdiger Pipkorn’s 35^th SS- und Polizei-Grenadierdivision and SS-Brigadeführer Fritz Schmedes’s 36^th Waffen-Grenadierdivision der SS) were positioned the Neisse river together with General Georg Jauer’s Panzerkorps 'Grossdeutschland' (Generalmajor Hermann Schulte Heuthaus’s Panzergrenadierdivision 'Brandenburg', Generalleutnant Otto Heidkämper’s Division Nr 464, Generalmajor Gerd von Below’s Division zbV 615 and a Kampfgruppe of Generalmajor Hans-Ernst Kohlsdorfer’s 545^th Volksgrenadierdivision).

On 15 April, Soviet reinforced infantry companies crossed to the western bank of the Neisse river at the fall of night to conduct reconnaissances in force of key areas of the planned offensive zone. These encountered organised and strong German fire resistance, however, and during this night engagement, the Germans abandoned their forward trenches and fell back into their second trench line.

At 06.15 on 16 April, the Soviet artillery preparation began, this taking into account the Soviet knowledge of the German tactic of leaving the first trench line only to reoccupy it after the Soviet barrage had ended: after a short bombardment of the first line of trenches, the Soviet artillery now concentrated its fire on the second trench line. At the same time, boats were brought up for the infantry’s river crossing, and at 06.55, as the artillery barrage shifted deeper into the German positions, a smokescreen covered the crossings of the Soviet reinforced leading battalions. After the assault wave had had seized bridgeheads on the western bank, the engineers began to erect bridges, and after 50 minutes these pontoon-based bridges were ready, followed after two hours by bridges to support 30-ton loads, and finally after four to five hours by rigidly-braced bridges capable of carrying loads of up to 60 tons. As a result, the main force’s leading echelon crossed the river on one hour, even before the artillery preparation had come to an end.

The 3^rd Guards Army’s 149^th Division attacked from the south-east into Forst, which the Germans had turned into a major stronghold, and by 18.00 was fighting for the city centre. From the east, the assault on Forst was assisted by one division of the LXXVI Corps. In general, though, the advance of the 3^rd Guards Army was behind schedule and amounted to a figure between 2.4 and 3.75 miles (4 and 6 km).

The 3^rd Guards Tank Army moved forward in the area to the south of Forst, and by the evening had started to fight for Domsdorf and Gross Schacksdorf. During the day, the army covered 5.6 miles (9 km), which was half of the 11.2 miles (18 km) laid down in the plan.

Advancing in the centre of the Soviet formation, the 13^th Army became the offensive’s leading element as it took Gross Kelzig and Klein Kelzig by evening and advanced 8.1 miles (13 km).

The 5^th Guards Army, advancing on the left flank, had to commit part of its strength to the elimination of the German bridgehead on the eastern bank of the Neisse river, and in the day advanced only 5 miles (8 km).

As a result of their error in assessing the probable Soviet plan, the Germans now found that their reserves were far to the south, so only Generalmajor Heinrich-Hermann von Hülsen’s 21^st Panzerdivision moving from Breslau to Berlin, and Generalmajor Otto-Ernst Remer’s Führer-Beglietdivision moving toward Spremberg, were available for redeployment to the area of the Soviet breakthrough. At about 12.00 on 16 April, SS-Obersturmbannführer Franz Roestel’s 10^th SS Panzerdivision 'Frundsberg' received an order to move to the north, a task made difficult by the fact that it had to move on its own without much in the way of fuel, but on the last dregs of this fuel managed to take up defensive positions between Cottbus and Spremberg.

Realising that any loss of time makes it possible for the Germans to ready a more effective defence, Lelyushenko decided that his 4^th Guards Tank Army was to continue its offensive during the night. He assigned the X Tank Corps the task of capturing a bridgehead on the western bank of the Spree river in the area to the north of Spremberg, and the VI Guards Mechanised Corps another bridgehead in the area to the south of Spremberg.

On the night of 17 April, the Germans launched a counterattack toward the southern outskirts of Forst, but this was driven back. During the day, the encirclement and then the destruction of German forces in the Forst area continued. By sending forward second-echelon forces, the 3^rd Guards Army was able to effect a useful regrouping: the CXX Corps now advanced to the west, and the LXXVI Corps stormed Forst.

During the night offensive, the 3^rd Guards Tank Army captured Zimmersdorf and continued its assault to the west, engaging in a night battle that ended in a Soviet tactical success but led at 10.00 to a German counterattack followed by units of the 21^st Panzerdivision which, advancing from the north and south, sought to encircle and destroy the Soviet units that had moved the farthest forward. All the German attacks were repelled, but the fighting was severe.

During the morning of 17 April, the armour of the 4^th Guards Tank Army overtook the infantry and forged forward, but the Soviet forces failed at this time to seize bridgeheads to the north and south of Spremberg.

Meanwhile, Schörner was feeding reserves into the 1^st Ukrainian Front’s offensive zone. The commander of the 10^th SS Panzerdivision 'Frundsberg', SS-Brigadeführer Heinz Harmel, who had established his headquarters in the town of Reutze to the west of Spremberg, was ordered by Gräser, the commander of the 4^th Panzerarmee, to close the gap between Cottbus and Spremberg with a counterattack.

On the evening of 17 April, Konev ordered an attack toward the Spree river, and at much the same time Konev spoke by radio with Iosef Stalin and received permission to turn the 1^st Ukrainian Front’s tank armies toward Berlin, and thus a right angles to the axis which had first been planned. Konev immediately ordered the 3^rd Guards Tank Army and the 4^th Guards Tank Army to break into Berlin from the south on the night of 20/21 April: on 21 April the tank armies were to take Potsdam and the south-western sector of Berlin, built-up areas were to be bypassed, and protracted frontal assaults were to be avoided.

On 18 April, German reserves withdrawn from quiescent sectors of the front began to approach Forst. The Soviet command decided not to encircle Forst and thereby turn it into a besieged 'fortress', for whose siege at least one infantry corps would have to be committed, so the garrison was allowed to withdraw to the north. Konev’s new order gave the 3^rd Guards Tank Army no new tasks, as before turning to Berlin it was still necessary to cross the Spree river. Taking advantage of the fact that the German defence was concentrated in focal areas, the VII Guards Tank Corps used forest roads during the afternoon of 18 April to reach and cross the Spree river in the area to the north of Spremberg. Konev entered the area later in the day and decided to lead all three corps of the 3^rd Guards Tank Army through this crossing. The Soviet forces could now offer an effective combination of offence and defence, and this facilitated the defeat of the 21^st Panzerdivision's counterattacks.

After encountering stubborn German resistance in the Spremberg area, the 4^th Guards Tank Army began to bypass the city from the north and south as it sought to reach the Spree river outside the built-up area. In the evening, the army managed to force the river in two places, and a crossing for tanks was immediately created at the northern bridgehead. As a result, on the third day of the offensive two combined-arms and two tank armies were able to overcome the entire depth of the German defence on the Neisse river and enter the major battle zone. The Germans lacked the reserves needed for counterattacks or the restoration of the front in this area, and the way to Berlin lay open to the Soviet forces. After this time, the Soviet offensive was divided into several separate battles: some of the Soviet forces continued fighting for Cottbus, two tank armies advanced to Berlin, and the combined-arms armies continued their offensive to the wester.

The 3^rd Guards Army, which was advancing on Cottbus, was attracting German reserves. As a result, Cottbus was defended by units of SS-Oberführer Dr Oskar Dirlewanger’s 36^th Waffen-Grenadierdivision der SS, Generalleutnant Johannes Baessler’s 242^nd Division, Generalleutnant Harry von Kirchbach’s 214^th Division, Generalleutnant Hans Schmidt’s 275^th Division, the 21^st Panzerdivision and the reconnaissance battalion of the 10^th SS Panzerdivision 'Frundsberg'. On 19 April, Gordov set his troops the task of passing four infantry divisions round Cottbus to reach Kolkwitz. Gordov’s plan was to deliver the main blow with his army’s left wing, bypassing the city to the north-west and thereby cutting German communications to the west. Taking advantage of the crossings of the Spree river in the sector of the neighbouring 13^th Army, Soviet troops began the rapidly development of their an offensive to the north and north-west, and by the evening of 20 April they had cut the railway linking Cottbus and Calau, and neared the Autobahn linking Berlin and Breslau in the area through which its passed to the south of Cottbus.

Since the main roads passed through Cottbus, which had therefore to be taken to ensure the continued logistical support of the forces advancing on Berlin, Konev on 20 April travelled to Gordov’s headquarters. With Konev’s permission, the 25^th Artillery Breakthrough Division was left at the disposal of the 3^rd Guards Army for another six hours before it moved toward Berlin. With this division’s support, the CXX Corps overcame Cottbus’s outer defences and entered the city’s eastern sector. By the end of 21 April, the German forces in the Cottbus area were surrounded on their eastern, southern and western sides, leaving them the sole option of withdrawing to the north and this into the swampy area lying there. At night, the XXI Corps also broke through to the city, and by 13.00 on 22 April the city was in Soviet hands. Exploiting this success, the Soviets pushed farther to the north toward the line of the Spree river.

In the Berlin area, on the morning of 19 April the swift offensive of the 1^st Ukrainian Front’s two tank armies began on the axis to the north-west. By 15.00 the 53^rd Guards Tank Brigade of the 3^rd Guards Tank Army had occupied a large road nexus at Fetschau, and the 52^nd Guards Tank Brigade and the 22^nd Guards Motorised Brigade, which were following, were engaged in clearing the area of the garrison’s remnants. By 19.00 the 53^rd Guards Tank Brigade had occupied Gross Lubenau , and the 51^st Guards Tank Brigade had taken Boblitz. The left flank of the VII Guards Tank Corps was led to the north-west by the 56^th Guards Tank Brigade, which had taken Casel by 14.00, Ogrozen by 15.00 and then Calau.

Leading the 4^th Guards Tank Army was the X Guards Tank Corps. During the day, the corps' 63^rd Guards Tank Brigade in the van covered 43.5 miles (70 km). The Soviet force had to bypass small centres of resistance, but was nonetheless moving into an operational void. The Soviet tank armies' deep breakthrough finally cut off General der Artillerie Kurt Wäger’s V Corps of the 4^th Panzerarmee, and during the evening of 19 April the corps was reallocated to Busse’s 9^th Army. Busse immediately ordered his new formation to leave only a weak cordon on the Neisse river and position between Lubben and Halbe.

On 20 April, and without meeting serious resistance, the Soviet tank forces continued their offensive. By the evening of the same day, the 53^rd Guards Tank Brigade had reached Berlin’s outer defence ring. In general, the 4^th Guards Tank Army was able to move in march rather and combat order, but the formations were nonetheless behind schedule, and by the evening of 20 April Konev began to realise that his plan to break through to Berlin was crumbling. At 19.40 he sent an order to Rybalko and Lelyushenko stating that Marshal Sovetskogo Soyuza Georgi K. Zhukov’s 1^st Belorussian Front was only 6.2 miles (10 km) from Berlin’s eastern outskirts, and that the two tank armies were to break into Berlin during the night. At 23.50 Konev demanded that Rybalko continue the attack on Berlin through the night so that his 3^rd Guards Tank Army was in the German capital by the morning of the following day.

Lelyushenko’s 4^th Guards Tank Army was now excluded from the order as by that time it had almost completed the turn of its front to the west.

After receiving Konev’s instruction to continue the offensive through the night, Rybalko ordered his 3^rd Guards Tank Army to enter the area bounded by the Autobahn circling Berlin and, for the first time since the beginning of the operation, with its subordinate corps deployed in line abreast. However, on the night of 20/21 April and during the afternoon of 21 April, the army had first to fight its way through a narrow defile between two swamps to the east and west of Baruth and the forest to the north of it: this area lay within the outer ring of Berlin’s defences. and it was only at 14.00 on 21 April that the Soviets forces passed from the Baruth to the Zossen area.

The course of events in the Baruth and Zossen area led to a shift of the 4^th Guards Tank Army’s axis back toward Berlin. At 14.55 Lelyushenko ordered the X Guards Tank Corps into a maximum-effort onslaught to bypass Luckenwalde, continue its rapid offensive toward Bergholz-Rehbrücke, Stahnsdorf and Zehdendorf, and take the south-western area of Berlin off the march.

By 22 April, the 3^rd Guards Tank Army’s advance had accelerated significantly and by the end of the day the IX Mechanised Corps had reached the Teltow Canal on a wide front. The VI Guards Tank Corps had captured Zossen but was then brought to a halt by a demolished bridge, but taking advantage of the ford to the east of the city and the only partially blown railway bridge, the corps continued its offensive, and by the evening had taken Teltow. Aware of the danger to his extended flank, Rybalko concentrated a reserve in the area to the south-east of Zossen with an order to prevent any attempt by the 9^th Army to break through to Berlin.

On 23 April there was a lull in the fighting. Elements of the 3^rd Guards Tank Army finally received the opportunity the army needed to rest and bring up men, ammunition and equipment from its rear. Active operations were continued only by the 71^st Guards Mechanised Brigade of the IX Mechanised Corps, which advanced to the east along the Berlin ring road. On the same day, the X Guards Tank Corps of the 4^th Guards Tank Army reached the Teltow Canal in the area of Stahnsdorf and there paused to allow its supporting infantry to arrive.

While the 3^rd Guards Tank Army and attached units began the assault on Berlin, the 4^th Guards Tank Army continued to fight for the crossings over the Havel river in the area to the south-east of Potsdam. On 25 April, the VI Guards Mechanised Corps crossed the river and at 12.00 linked with units of the 328^th Division of General Major Pavel M. Perkhorovich’s 47^th Army in the 1^st Belorussian Front, thereby completing the encirclement of Berlin from the west. By 27 April, the 4^th Guards Tank Army and the 47^th Army had completed the destruction of the German forces in the Potsdam area.

Originally conceived as an operation to break through the German front on the Neisse river and advance to the west, as a result of Konev’s ambitions the offensive became divided into two as the 'Cottbus-Potsdam Offensive Operation' and the 'Spremberg-Torgau Offensive Operation' and became what was in effect the southern component of what developed as a race to Berlin between the forces commanded by Konev and Zhukov. Nevertheless, the rapid progress of the Soviet forces toward Berlin made possible the encirclement of the 9^th Army in the Halbe 'cauldron', and this greatly facilitated the subsequent Soviet assault on Berlin.