General Clark rides into Rome. This triumphant moment for General Mark Clark came at a price. His failure to follow the agreed plan enabled the German forces to withdraw north of Rome intact.
Allied leaders then drew up a new plan, this time finally using their full resources, not just part of their armies. The bulk of the Eighth Army would capture Monte Cassino, while the Fifth Army attacked nearer the coast and the troops at Anzio cut communications between the Gustav Line and Rome. This offensive, codenamed Operation Diadem, was to be launched in the late spring. In the meantime, a major air offensive, Operation Strangle, would target German supply lines further to the north. In the event this had only limited success.
Diadem itself was finally launched on the night of May 10/11. French troops of the Fifth Army finally unlocked the Gustav Line defenses, breaking through some 12 miles (20 km) south of Cassino. Monte Cassino itself fell to a Polish corps serving with the Eighth Army. The Germans began retreating to the Caesar Line between Rome and Anzio and the Allies began their advance on Rome. On May 23 there was a breakout from the Anzio beachhead and, two days later, this advance linked up with the main body of the Fifth Army.
A misguided change of plan
The Fifth Army was then meant to cut off the retreat of the German forces from the Cassino area. But its commander, General Mark Clark, decided to head straight for Rome (his reason for this is still unclear). By the time the Fifth Army broke through the Caesar Line, the threatened German forces had escaped. On June 5 Clark entered Rome, but even this pointless triumph was immediately overshadowed by news of the D-Day landings in France the next day. The Allies followed up the German forces north of Rome, but their withdrawal to new and tough defenses, the Gothic Line, was very skilful.
The task of the Allied forces became more difficult from the second half of July, when many French and American soldiers were withdrawn from the Italian front to take part in the landings in the south of France. From the fall of 1944 through to the spring of 1945, the Allied attacks would again be poorly coordinated. They would make slow and difficult progress against increasingly determined German defense.
The Germans now built a new line of defense, the Gothic Line, again taking advantage of the natural barriers provided by mountains and river valleys.
The British Eighth Army managed to get through the German defenses, but several more river lines and the autumn rains slowed its advance. The US Fifth Army also penetrated the Gothic Line, but was halted by heavy casualties. By the end of the year, the British had come to a halt, too, and General Alexander decided to await spring before staging his final offensive.