Sidestepping the Germans at Cassino by landing at Anzio had seemed such a simple concept when Churchill met the Allied commanders at Christmas. It proved to be quite easy to organise an amphibious landing at short notice – but quite another to breakout of the small bridgehead that was then established.
Now that the Gustav line had broken and the Germans were falling back, the Anzio positions offered the Allies another opportunity. If they could break out from the beachhead in sufficient strength they would be able head directly inland and cut off the Germans retreating from Cassino. The German forces would be squeezed between the two Allied attacks and would potentially suffer a great defeat.
Overseeing all on the ground was General Mark Clark:
On 22 May I moved permanently into the forward echelon of my head-quarters at Anzio in preparation for the break-out. . . . Almost every inch of space at Anzio was crowded with men, guns and ammunition in preparation for the attack. Any time the enemy ﬁred a shell in our direction it was almost certain to hit something, but we had taken what precautions were possible, and most of our supplies were protected by mounds of earth.
Before dawn on the morning of 23 May I went with Truscott to a forward observation post on the Anzio front, where just before six o’clock some ﬁve thousand pieces of artillery opened up on the enemy, whose positions were concealed by a morning haze.
The smoke and haze hid our movements, but in the next hour or so we could hear our tanks moving forward to the attack, and there was a dull rumble of aircraft overhead as bombers began to pour their bombs on the German positions. The beleaguered Anzio garrison was about to break out, with the town of Cisterna their ﬁrst objective.
The timing of the attack from Anzio again caught the enemy off-guard. As the artillery ﬁre suddenly ended our tanks drove through the smoke, followed by swarms of infantry that caught the enemy outposts unprepared. Some of the Germans in dugouts had to be dragged out with only part of their clothes on, completely unready for battle.
Our artillery had previously been aimed at speciﬁc enemy centres, which were heavily shelled, but the morning haze interfered with the German artillery observation and gave us an opportunity of making considerable progress before meeting firm resistance. The Germans were never able to recover from this initial setback, and their later counter-attacks were weak and poorly organized.