'Mackensen' was the German southern counterpart to the 'Litzmann' break-out from the Kamenets-Podolsky pocket to the north-west by Generaloberst Hans-Valentin Hube’s 1st Panzerarmee (17 March/3 April 1944).
In 'Mackensen', other elements of the 1st Panzerarmee broke out of the pocket in the same place, but then headed to the south-west across the Dniestr river and toward the Prut river before wheeling toward the north-west to link with Generaloberst Erhard Raus’s 4th Panzerarmee near Stanisław.
As a means of maintaining control and simplifying the chain of command during the break-out, Hube consolidated his force into three provisional Korpsgruppen (corps groups) each responsible, in its own zone, for both the conduct of the break-out attack to the west and the rearguard action in the east. The Panzer divisions of each Korpsgruppe were to spearhead the 1st Panzerarmee's attack, while the infantry divisions covered the rear. Two columns were to fight their way to the west. The northern and southern columns were General Kurt von der Chevallerie’s Korpsgruppe 'von der Chevallerie' and General Hermann Breith’s Korpsgruppe 'Breith' respectively, and the third grouping, based on the XLVI Panzerkorps, was General Hans Gollnick’s Korpsgruppe 'Gollnick'.
The break-out’s first objective was the seizure of locations at which the Germans forces could cross the Zbruch river. The Korpsgruppe 'von der Chevallerie' was to establish contact with Generalmajor Werner Marcks’s 1st Panzerdivision at Gorodok and Kampfgruppe 'Mauss' in the area between the Ushitsa and Zbruch rivers, and then to cover the northern flank of the 1st Panzerarmee in the area between the Ushitsa and Zbruch rivers before establishing a bridgehead across the latter at Skala. The Korpsgruppe 'Breith' was to recapture Kamenets-Podolsky, regain control of the road linking Kamenets and Khotin, and then establish a bridgehead across the Zbruch river to the north-west of Khotin. Korpsgruppe 'Gollnick', in close contact with the southern flank of the Korpsgruppe 'Breith', was to delay the Soviet forces below the Dniestr river before pulling back to hold a bridgehead at Khotin.
Hube’s 1st Panzerarmee was thus to break out to the north-west toward Tarnopol, where relief forces of SS-Obergruppenführer und General der Waffen-SSfrom Paul Hausser’s II SS Panzerkorps were to meet them, and arrangements were made with Generaloberst Otto Dessloch’s Luftflotte IV to assemble five air transport groups and a number of bomber wings at Lwów in Poland to fly essential supplies into the pocket.
The distance from Kamenets-Podolsky to Tarnopol is more than 155 miles (250 km), and the break-out over this distance meant movement over universally muddy terrain and several rivers, and it was believed that the Soviets would act as they had at Stalingrad, and therefore make their strongest resistance along this line.
On 27 March, the advance guard of the 1st Panzerarmee broke out of the pocket in a westerly direction toward the Zbruch river and the rearguard began a fighting withdrawal, with the rest of the 200,000 German troops between them. The attack of the advance guard proceeded well, the northern column quickly taking three bridges over the Zbruch river but the southern column was battered by a counterattack delivered by General Leytenant Vasili M. Badanov’s 4th Tank Army, which penetrated deep into the pocket and took Kamenets-Podolsky. The loss of this major road and rail hub meant that the escaping Germans had to detour around the city, greatly slowing their movement. A counterattack soon cut off the Soviet forces in the city, however, and the break-out once more gathered speed. Moving by night as well as day, the Kessel (cauldron, or combat area) proceeded steadily, and soon established bridgeheads across the Seret river.
While the 1st Panzerarmee escaped to the west, Marshal Sovetskogo Soyuza Georgi K. Zhukov and General Ivan S. Konev, the Stavka representative and commander of the 2nd Ukrainian Front respectively, continued to believe that the German forces' major break-out attempt would be made to the south, and ordered the attacks on the northern and eastern flanks of the pocket to be intensified. These attacks achieved little, and many fell on positions which had been abandoned as the German troops withdrew to Proskurov. Despite the German attacks to the west, the Soviets continued to increase their troop density to the southern flank of the pocket in anticipation of an attack that would, in fact, never be made.
On 30 March, Generalfeldmarschall Erich von Manstein, commander of Heeresgruppe 'Süd', was informed by the Oberkommando des Heeres that he had been relieved of command. It was clear that von Manstein’s many heated arguments with Adolf Hitler about the strategic direction of the war on the Eastern Front had not been forgotten, and Hube was on his own.
On the following day, the Soviets began to react. A strong armoured grouping of the 4th Tank Army launched an assault in the north between the Seret and Zbruch rivers. The southern arm of Hube’s advance guard turned and halted the Soviet assault, severing its supply lines and thereby halting the 4th Tank Army’s armour. Despite the fact that he was now taking the break-out attempt seriously, Zhukov did not move to block the escaping Germans, and the way to Tarnopol was still open.
Despite the heavy fall of snow, a paucity of supplies, and encirclement, constant movement meant that 'pocket fever' did not affect the 1st Panzerarmee. The men were still moving in good order and obeying discipline, while desertions were almost non-existent: this was all in stark comparison to the panicked situation within the Stalingrad and Korsun encirclements.
By 5 April, the advance guards of both the northern and southern columns had reached the Strypa river, and on the following day, near Buczacz, met the probing reconnaissance elements of Hausser’s SS divisions. In more than two weeks of heavy combat, in dire weather conditions and constantly short of supplies, the 1st Panzerarmee had escape from its encirclement and in the process suffered only modest casualties. The army was then put back into the German line and established itself between the Dniestr river and the town of Brody.
During their two-week escape, Hube’s forces had destroyed 357 tanks, 42 assault guns and 280 pieces of artillery, as well as causing severe casualties to the Soviet’s attacking forces. von Manstein’s clear and rapid thinking had combined effectively with Hube’s operational planning and tactical skill to ensure that the 200,000 men of the 1st Panzerarmee escaped the fate of Generalfeldmarschall Friedrich Paulus’s 6th Army Stalingrad. However, while Hube’s troops were still disciplined, and equipped with light and personal weapons, only 45 armoured vehicles had escaped, so the 1st Panzerarmee was no longer capable of undertaking large-scale offensive operations and required thorough rehabilitation.