In early 1944, two Allied armies were ready to launch a massive assault against German forces in central Italy so they could then march northwards to Rome. There were three routes available to get there. The fastest one passed through the Liri valley, but the entrance was blocked by the rugged Monte Cassino massif, with its hilltop medieval monastery and the town below. In front of them ran the Gustav Line: the most formidably constructed defensive line the Western Allies would ever come up against. The second possible route would be to outflank the Gustav Line to reach the valley, but they would then also have to capture the innumerable rough peaks and ridges along the massif, on a treacherous terrain that only favoured the defenders. The third and final option would be to breach the Gustav Line directly in front of the town, which would mean engaging in costly house-to-house fighting until they dug out the very last of the stubborn German paratroopers lurking beneath the rubble. They decided to try all three, but none of them were easy, and all proved deadly.