By October 1943, the German 17th Army had been forced to retreat from the Kuban bridgehead across the Kerch Strait to Crimea. During the following months, the Red Army pushed back the German forces in the southern Ukraine. In November 1943, they eventually cut off the land-based connection of 17th Army through the Perekop Isthmus. Hitler prohibited a sea evacuation of 17th Army because he thought the Red Army could use the Crimean Peninsula to launch air attacks against Romanian oil refineries. In November 1943, the Russian launched a massive amphibious assault at two locations on the eastern coast of the Crimea, but its units were unable to prevent an Axis counterattack that collapsed the southern bridgehead. The Red Army held the bridgehead at Yenikale, from which they launched further offensive operations, culminating in a huge offensive in April 1944. Although the 17th Army bitterly contested every bit of ground, it was unable to stop the advance. Soviet forces reached Kerch on
