The 'Tartarenwall' was the German defensive position on the Perekop isthmus separating Crimea from the rest of the USSR (8/10 April 1944).

The defence was breached by the Soviet 'Crimean Strategic Offensive' (8 April/12 May 1944), and the German forces then withdrew toward Sevastopol in 'Adler' (v).

Generaloberst Erwin Jaenecke’s 17^th Army of Generalfeldmarschall Ewald von Kleist’s Heeresgruppe 'A' (from 30 March 1944 Heeresgruppe 'Südukraine') had sat out the winter of 1943/44 in Crimea after its land communications with Generalfeldmarschall Erich von Manstein’s Heeresgruppe 'Don' had been severed by the first phase of the great Soviet advances in the 'Lower Dniepr Offensive Operation' of 26 September/20 December 1943. After the last hope that von Manstein’s army group might come to its relief had faded in November 1943 and in the same month the Soviets had seized beach-heads on the southern shore of the Sea of Sivash and on the Kerch peninsula in the 'Kerch-Eltigen Offensive Operation' of 31 October/11 December 1943, Generaloberst Kurt Zeitzler (chief of the Oberkommando des Heeres’s general staff), von Kleist and Jaenecke had agreed the 17^th Army should be removed from Crimea on the grounds that in the long run the peninsula could not be held, its troops were needed on the main part of the Eastern Front, and any further diversion of troops there would be a total waste of resources. Adolf Hitler had insisted that the army must remain, however, and during the winter had removed formations from Heeresgruppe 'Süd' and Heeresgruppe 'A' to increase the 17^th Army's strength in German formations from one to five infantry divisions, as well as two self-propelled assault gun brigades. Maresal al România Ion Antonescu, the leader of Romania, would much rather have removed the army’s seven Romanian divisions, but had been persuaded to leave them with the 17^th Army.

This army, while maintaining and improving its northern defence of the 'Tartarenwall' on the Perekop isthmus, had managed during the winter to reduce the Soviet beach-heads to two very small areas, one at the south-eastern end of the isthmus on the southern side of the Sea of Siwash and the other on the easternmost tip of the Kerch peninsula. Senior German and Romanian commanders all appreciated, however, that in the event the Perekop isthmus was lost, the only other place the army could make a determined stand was at Sevastopol. It had built the 'Gneisenau-Linie' in an approximate arc centred on Simferopol, with its north-western end on the sea at Saki to the north of Sevastopol and its south-eastern end of the sea at Alushta to the east of Sevastopol, but had troops to fight only a rear-guard action there until the main force had fallen back into the defences of Sevastopol.

On 7 April 1944 Generaloberst Ferdinand Schörner, commander since 25 March of Heeresgruppe 'A' (Heeresgruppe 'Südukraine' from 31 March), inspected the defences of Crimea and characterised them as first class, and even went as far as to report up the chain of command that Crimea could be held for a lengthy period.

On the morning of the very next day, General Fyedor I. Tolbukhin’s 4^th Ukrainian Front attacked to the south at the start of the 'Crimean Strategic Offensive Operation', with General Leytenant Georgi F. Zakharov’s the 2^nd Guards Army on its right and General Leytenant Yakov G. Kreizer’s 51^st Army on the left; at the same time General Andrei I. Eremenko’s Independent Coastal Army surged to the west from its Kerch lodgement at the eastern end of the peninsula. The 4^th Ukrainian Front was supported by the air arm of the Black Sea Fleet as well as General Polkovnik Konstantin A. Vershinin’s 4^th Air Army.

The 'Tartarenwall' defences manned by General Rudolf Konrad’s XLIX Gebirgskorps held, but General de brigadâ Gheorghe Niculescu’s Romanian 10^th Division, holding half of the Sea of Sivash bridgehead line, was badly shaken on the first day of the Soviet offensive and collapsed on the following day. That night Jaenecke ordered the defenders to fall back to the base on the Perekop isthmus, and Schörner informed Zeitzler the retreat to Sevastopol might have to begin any minute and that Jaenecke should therefore be permitted to make the appropriate decision. He was confident, Schörner said, that neither Jaenecke nor Generalmajor Wolfdietrich Ritter von Xylander, his chief-of-staff, would make and implement any over-hasty decision. Almost inevitably, Hitler refused and instead sent Zeitzler to the army group headquarters, which he reached on 10 April to learn that the Soviets had driven into the peninsula’s interior and that the first stage of the retreat had therefore been ordered. Since the first stage, as planned, involved primarily the removal of the troops of General Karl Allmendinger’s V Corps from the Kerch peninsula, Hitler approved. The, on the following day, Hitler learned that orders for all formations and units to withdraw to the 'Gneisenau-Linie' had also been issued, he became furious and accused Jaenecke of having lost his nerve. As the German and Romanian formations and units retreated to the west from Kerch, the Independent Coastal Army began to exert greater pressure from the east.

When Schörner and Generalleutnant Walter Wench, the chief-of-staff of Heeresgruppe 'Südukraine', who was in Crimea at the time, argued that Jaenecke’s decision had in fact been wholly necessary, Hitler permitted a withdrawal to the 'Gneisenau-Linie' defences and, should it become necessary, to Sevastopol, but directed that the latter was then to be held indefinitely. All, including Hitler, had previously believed that when the retreat began it would have to continue into its logical conclusion, an evacuation. Schörner reported that the 'Gneisenau-Linie' and Sevastopol could not be held for more than one month at the most, and he had already instructed the navy to send the first '60,000' convoy from Constanţa in Romania to remove service troops.

On 12 April Soviet tanks broke into the 'Gneisenau-Linie' at several locations, and on the following day the Soviets took Simferopol. On 16 April, with the Soviet forces close on their heels, the rearguards of the 17^th Army completed the 'Adler' (v) retreat into Sevastopol’s main defence line. One day later Hitler ordered Heeresgruppe 'Südukraine' to evacuate all the troops and equipment not needed for the defence, but at the same time demanded that Sevastopol be held.