From the Gustav Line to Rome and Florence
The Germans, threatened by the Allies, started organizing and strengthening their defense lines on the Apennines, the most important being the Gustav Line that followed the course of the rivers, Garigliano, Rapido and Sangro. On 22 January 1944 the attempt to circumvent the Gustav Line with the Anzio landings failed.
Needless Allied bombings destroyed the ancient abbey of Montecassino, but the Germans resisted until May when the Polish and French troops broke through the Gustav Line, surrounded the Hitler Line and overcame the German defenses.
On June 4, 1944, the Allies liberated Rome and installed the Bonomi government, they continued on northwards, reaching and occupying Florence which had already been liberated by partisans on August 11, 1944.