Following up on the Allied success on Sicily in July and August 1943 (Operation husky), the American Fifth Army landed at Salerno, a city on the western coast of Italy, on 9 September 1943 (Operation avalanche) and began to push north. With rugged mountain ranges, heavy rains, and stiff German resistance barring the advance, Allied progress was slow. In late 1943, having broken through the Volturno Line (a German defensive line anchored on the Volturno River), the Allies found themselves up against the Gustav Line. To force the German commander, Field Marshal Albert Kesselring, to fight in two directions (west and south), the Fifth Army's commander, Lieutenant General Mark Clark, planned Operation shingle, an amphibious landing at Anzio/Nettuno, north of and behind the Gustav Line. By landing at Anzio/Nettuno with a corps, Clark believed it would be possible to turn Colonel General Heinrich von Vietinghoff's Tenth Army out of the Gustav Line, thus opening the Liri Valley and the routes to Rome.
To prepare for the landing of Major General John Lucas's American VI Corps and its subsequent linkup with Fifth Army, Clark ordered attacks by the British X Corps and the U.S. II Corps. In order to seize key heights to protect the southern flank of II Corps as it began its attack up the Liri Valley, Lieutenant General Richard McCreery's X Corps assaulted across the Garigliano River on 17 January 1944. Failing to cross the river, the British attacked once more two days later but did not achieve their objectives. As a result, Major General Geoffrey Keyes's II Corps would assault across the Rapido River with its left flank exposed.
Keyes's plan to attack across the Rapido River and into the Liri Valley was simple. The 36th Infantry Division would move forward, with two regiments abreast, roughly 3 miles downstream from the town of Cassino; the 34th Infantry Division would attack with three regiments abreast north of Cassino. Beginning their strike on 20 January, the Americans immediately encountered stiff resistance from General der Panzertruppen (U.S. equiv. lieutenant general) Fridolin von Senger und Etterlin's German XIV Corps.
Throughout the night of 20 January, the Americans struggled to find their way through minefields, cross the river in rubber rafts and canvas boats, and erect footbridges. Sunrise the next morning exposed the Americans to accurate German artillery and rocket fire. Concerned with his losses, the 36th Infantry Division commander, Major General Fred Walker, prevailed on Keyes to delay a renewed effort until after dark. Attacking again on the evening of 21 January, the 36th Infantry Division suffered heavy losses without establishing a lodgment on the far side of the Rapido. Against Keyes's wishes, Clark authorized Walker to halt the attack on the morning of 22 January.
With the 36th Infantry Division stalled, Clark now intended to envelop Cassino from the north. Attacking on 25 January with the 34th Infantry Division and units of General Alphonse Juin's French Expeditionary Corps, the Allies soon ground to a halt. Once again, the soggy ground, a strong current, and determined German resistance frustrated Clark's efforts to capture Cassino. Over the next several days, the 34th Infantry Division, including the Nisei 100th Infantry Battalion, inched its way up and over the heights north of Cassino but was unable to capture the abbey or the town. By 11 February, the II Corps attack was spent, and the task for opening the Liri Valley fell to Lieutenant General Bernard Freyberg's New Zealand II Corps.
Believing the only way to capture Cassino was to eliminate the abbey from the commanding heights above the town, Freyberg received permission to bomb it, and on 15 February, waves of bombers dropped 435.5 tons of high explosives, reducing the abbey to ruins. Although the Germans had not previously garrisoned the abbey, its destruction allowed them to position troops amid the rubble and to strengthen their lines. Launching Operation avenger on 15 February, Freyberg's subordinates, facing the same problems as the Americans had earlier, fought with little success to capture Monte Cassino. Frustrated by his lack of progress, Freyberg ordered a halt to avenger after three days of fighting.
Freyberg set the next attack for 24 February. Called Operation dickens, the attack comprised two infantry divisions and a tank regiment. Believing a direct approach would prove more effective, Freyberg planned to attack frontally into the town of Cassino, but heavy rains delayed the operation until 15 March. Following the Italian Campaign's first massive carpet bombing, Freyberg's troops engaged in heavy fighting within the town and on the surrounding heights. For the next 10 days, II New Zealand Corps fought in close combat amid the ruins of Cassino with little effect. Because Freyberg failed to commit his reserves in a decisive manner, his conduct of the operation resulted in the heavy casualties he had hoped to avoid. By 24 March, the II New Zealand Corps attacks had halted, with the Germans still in possession of portions of Cassino and the abbey's ruins.
By mid-April, the Polish II Corps, commanded by Lieutenant General Wladyslaw Anders, began to move into the line opposite Cassino. As part of an Allied deception plan, activity along the Gustav Line almost completely ceased. On 11 May, the Allies attacked with Fifth Army and the British Eighth Army, and although the offensive caught the Germans by surprise, casualties among the Poles were still high. Fifth Army's progress south of Cassino in the Liri Valley, however, rendered Monte Cassino unimportant to the Germans' defense. On the evening of 17 May, the defenders withdrew, and the next day, the Polish II Corps occupied Monte Cassino, completing a four-month battle for the heights. Casualties for the Allies numbered some 120,000; the Germans suffered almost 130,000. David M. Toczek
Blumenson, Martin. U.S. Army in World War: European Theater of Operations—Salerno to Cassino. Washington, DC: Office of the Chief of Military History, Department of the Army, 1969.; Blumenson, Martin. Bloody River: The Real Tragedy of the Rapido. Boston: Houghton Mifflin, 1970.; Ellis, John. Cassino, the Hollow Victory: The Battle for Rome, January–June 1944. New York: McGraw-Hill, 1984.; Piekalkiewicz, Janusz. Cassino: Anatomy of the Battle. Harrisburg, PA: Historical Times, 1988.
David M. Toczek