It took four attacks to break the German defence line in May 1944. After heavy fighting, a Polish unit reached the top of Monte Cassino and planted the Polish flag among the ruins of the destroyed monastery. The road to Rome lay open. On 4 June 1944, American troops seized the Italian capital.

Mark Clark was responsible for operations at both Anzio and Cassino. Under Clark, and in direct command of the two-division attack at Cassino, was General Sir Bernard Freyberg. A New Zealander of imposing physical appearance and impressive reputation, Freyberg was a legendary hero of World War I.

The Italian government paid for the reconstruction of Monte Cassino, although Abbot Ildefonso Rea made the appeal to restore the monastery two years after it was destroyed. Before they could rebuild the abbey, they had to remove more than 900,000 cubic yards of rubble from the site.

In January, General Sir Harold Alexander, the British officer who commanded the two Allied armies in Italy, gave the signal to start the Rome operation.  General Clark, as commander of the U.S. Fifth Army, thereupon opened a massive attack at Cassino.