The Allies progress up the “boot” of Italy all but stopped when they hit a series of German defensive lines known collectively as the Winter Line. The lines ran from sea to sea, anchored by high points such as Monte Cassino. From January of 1944, until the breakout after the Anzio landing, the Allies threw everything at the Germans with little success. With Rome less than 100 miles away, the Allies decided on a risky move, an amphibious landing just North of the German defensive line.