In the winter of 1943 General Albrecht Kesselring withdrew his forces to what became known as the Gustav Line on the Italian peninsula south of Rome. Organized along the Garigliano and Rapido rivers it included Monte Cassino, a hilltop site of a sixth-century Benedictine monastery. Defended by 15 German divisions the line was fortified with gun pits, concrete bunkers, turreted machine-gun emplacements, barbed-wire and minefields. In December 1943, the Allied suffered heavy loses while trying to capture the monastery.
In January 1944, General Dwight D. Eisenhower and General Harold Alexander, Supreme Allied Commander in Italy, ordered an amphibious operation at Anzio, a small port on the west coast of Italy. This was to be combined with a new offensive on Monte Cassino. The main objective of the operation was to cut the communication lines of the German 10th Army and force withdrawal from the Gustav Line.
Attacks on Monte Cassino on 17th January resulted in the Germans reserves moving to the Gustav Line and on 22nd January the 6th Corps landed at Anzio. Lucas decided not to push straight away to the Alban Hills. This enabled General Heinrich Vietinghoff to order the 14th Army to return to the area and contain the 6th Corps on the Anzio bridgehead. General Mackensen counterattacked on 15th February 1944 but this was halted by the American troops.
Winston Churchill was furious with Lucas and commented "I had hoped that we were hurling a wildcat onto the shore, but all we got was a stranded whale." General George Marshall accepted the criticism and Lucas was replaced by General Lucian Truscott.
On 18th May, 1944, Allied troops led by General Wladyslaw Anders (Polish Corps) and General Alphonse Juin (French Corps) captured Monte Cassino. This opened a corridor for Allied troops and they reached Anzio on 24th May. The German defence now disintegrated and General Mark Clark was able to take his forces direct to Rome which he liberated on 4th June.
Anzio played a vital role in the capture of Rome by giving me the means to employ a double-handed punch - from the beachhead and from Cassino - which caught the Germans in a pincer movement. Without this double-handed punch I do not believe we should ever have been able to break through the German defences at Cassino.
Orders for the operation were issued on 2 January. The objective was defined as to cut the enemy communications and threaten the German rear. Fifth Army was ordered to make "as strong a thrust as possible towards Cassino and Frosinone shortly before the assault landing to draw in enemy reserves that might be employed against the landing forces and then to create a breach in his front through which every opportunity will be taken to link up rapidly with the seaborne operation". Despite the switch, in all, of five divisions from Eighth Army to the Fifth Army, German resistance on the main front remained stubborn; and during the early critical days the British and United States divisions at Anzio had to fight unaided for their own salvation. Meanwhile, on the Adriatic sector. General Montgomery had continued with his attempt to break through the enemy's defensive system; but with even less success as the weather worsened and the enemy's strength increased.
Against a less formidable foe an operation such as we had devised would have succeeded; but I think we may well have underestimated the remarkable resilience and toughness of the Germans, in expecting them to be frightened by such a threat to their rear.
Hitler's orders to Kesselring were to hold on to Cassino at all costs, for political reasons, and to eliminate the Anzio landing. The withdrawal of the Hermann Goring division from Italy was cancelled, and Hitler told Kesselring that he would be reinforced by two motorized divisions, three independent regiments, two heavy tank battalions and some heavy and medium artillery units. Thus the enemy refused to weaken his battlefront at Cassino by drawing back formations to deal with the landings.
Every time we attacked Kesselring in Italy we took him completely by surprise; but he showed very great skill in extricating himself from the desperate situations into which his faulty intelligence had led him. I feel now that he would not, in these circumstances, have altered his dispositions on the main front to any great degree until he had tried every means to eliminate the threat to his rear. Nor need his determination be doubted. The forces under his command had been engaged in a continuous retreat for almost a year since November 1942, a retreat that had brought them just short of Alexandria to just north of Naples - and it was time to put a stop to it.
Unlike my operation in Calabria, the landing at Anzio went exactly according to plan. We lost fewer men than the Americans had lost on the exercise at Salerno the previous week. The surprise we achieved was so complete that we even captured some German officers in their pyjamas. The real trouble came later, in the months when the beach-head was under siege, so brilliantly described by Raleigh Trevelyan in Rome 1944.
Though the landing itself went well, Anzio was a tactical failure. Some of the forces which should have taken part were withdrawn for the landing in France, so we never had enough troops to hold both the beachhead and the Colle Laziale, which dominated the beachhead from a few miles inland. Even if, as armchair critics have claimed, a bolder commander could have entered Rome in those first few days, his troops would have been cut off and wiped out at leisure. But the Germans made greater strategic mistakes. They gravely weakened their forces on more important fronts in the vain hope of wiping out the beachhead. So Anzio on balance turned out to be a success. Victory in war, as in politics, often goes to the side which makes fewer or less serious mistakes, not to the side with the greatest positive virtues.