On January 17, 1944, U.S. 5th Army (comprising American, British, and French units) attacked the Gustav Line, including a thrust at Monte Cassino and a crossing over the Rapid River, which made some progress. The attack also was intended to divert German attention from an Allied amphibious assault at Anzio, which was carried out by U.S. VI Corps (comprising one American and one British division) on January 22, 1944. The Anzio landings were aimed at flanking the Winter Line, and a two-pronged offensive, with U.S. VI Corps from the east and U.S. 5th Army from the south, was envisioned to trap and destroy German 10th Army at the Gustav Line.
The Anzio landings caught the Germans by surprise, but General John Lucas, U.S. VI Corps commander, balked at breaking out from the beaches, fearing that his forces, consisting of two divisions and without tanks, were insufficient to make a flanking attack toward the Gustav Line as well as to hold out against a likely German counter-attack. Instead, General Lucas dug in his forces along a defensive line at the Anzio beachhead, which gave the Germans time to react.
(Taken from Italian Campaign – Wars of the 20th Century – World War II in Europe: Vol. 6)
Battle of Italy The Allied campaign in Italy, as in the entire North African and Mediterranean region as a whole, came about from a compromise between American and British military planners in response to prodding by Soviet leader Joseph Stalin that the Allies open a second front in the West to ease German pressure on the beleaguered Eastern Front, which was defended by the Soviet Union. The U.S. military high command wanted an immediate campaign in France, deeming that this was the quickest way to end the war. The British desired an offensive in the Mediterranean region for control of the vital sea lanes and for other strategic reasons, and particularly to carry the war to Italy, which British Prime Minister Winston Churchill called the “soft underbelly” of the Axis. In the end, the British and Americans agreed that a cross-English Channel invasion of France would be launched in 1944, but that an operation into Italy would also be carried out, which could achieve any of the following strategic aims on the continent: Italy would be knocked out of the war; if not eliminated from the war, Italy would be forced to withdraw its troops from occupied Europe to defend the homeland; and with the Italian withdrawal, German manpower and resources would be stretched further to help defend Italy and occupy territories vacated by the Italians.
For Germany, the loss of North Africa brought its southern European flank under threat. In November 1942, German forces occupied Vichy France, relegating the nominally independent French polity into no more than a puppet state. To counter a possible invasion of Italy from the south, the Germans planned (and did) exploit the rugged mountainous terrain of Italy, particularly the Apennine Mountains that stretch for much of the north-south length of the country. Italy shared a border with Greater Germany through Ostmark (Austria), and the Germans also were determined to defend Italy to protect the vital oil fields and mineral resources of the Balkan region.
Preparatory to the invasion, Britain and the United States launched air attacks in southern Italy, Sicily, and Sardinia, targeting airfields, port facilities, and industrial sites. On July 10, 1943, the Allies made amphibious landings in Sicily, with the U.S. 7th Army at the Gulf of Gela in the southwest and the British 8th Army south of Syracuse in the southeast. Allied naval gunfire easily overpowered the Italian coastal defenses, with the fiercest opposition coming from the Luftwaffe, which launched air attacks that sank and damaged several Allied ships. U.S. ground forces repulsed repeated German counter-attacks, and by July 15, 1943, the Allies had secured their bridgehead and were breaking out toward the north. The German-Italian forces quickly established defensive positions along Mount Etna in the northeast, stalling the advance of British 8th Army at Catania, and elements of U.S. 7th Army.
General George Patton, commander of U.S. 7th Army, then launched an attack toward central Sicily, and soon reached Palermo, Sicily’s capital located in the northeast, on July 23, 1943. U.S. forces then advanced along the northern coast, threatening to outflank the Axis forces on Mount Etna. The Allies breached the first line of defense, forcing the Axis to retreat to another set of defenses. But with the Allies also threatening to break through the second line, and British and American units also conducting flanking maneuvers along the coast, the Axis deemed their positions in Sicily untenable. On August 11, 1943, the Axis began to evacuate Sicily across the Strait of Messina for the southern Italian mainland, completing their withdrawal on August 17; some 40,000 German and 70,000 Italian troops were evacuated. The Allies captured over 110,000 mostly Italian troops, most of whom did not offer resistance.
For Italy, the loss of Sicily came as a shock, which was worsened by an Allied air raid on Rome on July 19, 1943 that destroyed civilian and military infrastructures. On July 25, 1943, the Fascist Grand Council stripped Mussolini of many powers, including control of the Italian military, which was turned over to King Victor Emmanuel III. The next day, the Italian monarch fired Mussolini as Prime Minister, and had him imprisoned. A new government was formed, led by the chief of the Italian Armed Forces, General Pietro Badoglio, who was appointed as the new Prime Minister.
The invasion of Sicily also forced Germany to withdraw some units in Russia, particularly from the ongoing Battle of Kursk (where the German offensive was already faltering), to confront the new threat. Thereafter, the Germans lost the initiative in the Eastern Front and would permanently be on the defensive, a situation they also would face in the Allied campaign in Italy.
General Badoglio declared his continued alliance with Germany, but secretly opened peace talks with the Allies. Negotiations lasted two months, and on September 8, the Italian government announced an agreement with the Allies, called the Armistice of Cassibile, where Italy surrendered to the Allies. Fearing German reprisal, King Victor Emmanuel II, General Badoglio, and other leaders fled from Rome and set up headquarters in Allied-controlled southern Italy. There, on October 13, 1943, the Badoglio government declared war on Germany.
The Germans, which had increased their military presence in Italy since Mussolini’s ouster a few months earlier, and had gained intelligence information that the new government was seeking a separate peace with the Allies, now sprung into action and disarmed Italian forces in Italy, France, and the Balkan regions, and seized important military and public infrastructures across Italy. Italian military units were unaware of the armistice, and thus were caught off-guard and generally failed to offer resistance to the German take-over. Then on September 12, 1943, Mussolini was rescued from captivity by German commandos in a daring raid, and two weeks later, was installed by Hitler as head of the newly formed fascist state, the Italian Social Republic, covering Axis-controlled northern and central Italy. Two rival governments now laid claim to Italy, and the former Italian Armed Forces became divided, fighting while aligned with one or the other side.
Meanwhile, in September 1943, the Allies were ready to invade mainland Italy after their capture of Sicily one month earlier. On September 3, 1943, the same day that the armistice was signed, British 8th Army units in Sicily crossed the Gulf of Messina and landed at Reggio di Calabria, at the southwestern tip, or “toe” of Italy (Figure 36). The landing was unopposed, as the Germans had already retreated north while the Italian coastal batteries were overwhelmed by Allied naval gunfire. Then on September 9, 1943, one day after the armistice was announced, the British made another amphibious landing at Taranto in southeast Italy, which also was unopposed. The Allies aimed the two landings to divert the Germans from the main landing at Salerno, some 200 miles further north off the western coast, which also was carried out on September 9, 1943 by the newly formed U.S. 5th Army (comprising one American and two British divisions). The Allies also anticipated that the Taranto-Salerno landings would exploit the confusion among the Germans by the sudden announcement of the armistice.
However, by the time of the armistice, the Germans were firmly established in Italy. And although many German units were diverted to disarm the Italian Army, a substantial force remained to guard against the expected Allied invasion. Furthermore, General Albert Kesselring, commander of German forces in southern Italy, correctly surmised that the main Allied landing would not be made in southernmost Italy, but rather in the vicinity of Salerno, Naples, or even Rome, where he concentrated German forces from their withdrawal from the south.
Thus, the British landings at Reggio di Calabria and Taranto were unopposed, and the ensuing British advance up the eastern coast facing the Adriatic Sea encountered only rear guard actions by small, retreating German detachments.
Furthermore, the Germans were not taken completely by surprise by the landing of U.S. 5th Army at Salerno. Almost immediately, German artillery batteries positioned at the hills east of Salerno opened fire on the beaches, pinning down Allied forces and preventing a breakout. With the arrival of reinforcements, on September 13, 1943, the Germans counter-attacked, with the brunt falling on the Americans, who came very close to relinquishing their beachhead and evacuating altogether. Allied naval and air firepower blunted the German attack; as well, more Allied troops were landed, together with increasing numbers of tanks and artillery pieces. Another German attack on September 16 also was stopped by superior Allied firepower. Then on September 17, with British 8th Army from the south closing in to link up with Allied forces at Salerno, the Germans retreated in good order northward to hastily prepared lines on the Apennines. The Allies then took Salerno, and on October 1, 1943, they entered Naples, which by then had suffered extensive destruction, caused by German scorched-earth actions as well as by Allied bombings. The Allies now controlled all of southern Italy.
The Allies advanced further north, with British 8th Army in the east along the Adriatic coast and U.S. 5th Army in the west, and in early October 1943, came upon the Volturno Line (Figure 36), a German temporary line across the Apennines extending to the Volturno River in the west and Biferno River in the east. After heavy fighting, the British and Americans broke through, and advanced to another set of German stalling defenses, the Barbara Line. In early November 1943, the Allies breached this second line, and on November 9, advanced to the vicinity of the Gustav Line, which was the German main defense system guarding the entrance to Rome.
On either side of the Gustav Line was a secondary line, the Bernhardt Line to the south and the Hitler Line to the north, these three lines collectively known as the Winter Line. In early December 1943, U.S. 5th Army reached the Bernhardt Line, breaching it by mid-January 1944 after subduing fierce German resistance, and advanced to the Gustav Line, where it would be stalled for the next several months by powerful German defenses. In the east, in late December 1943, the British 8th Army broke through the Gustav Line, but was unable to advance further because of wintery weather conditions and arduous mountain terrain. The Allied High Command then decided to focus on the western sector aimed at breaking through the Gustav Line for the advance to Rome.
German strategy for the defense of Italy relied on the natural defensive features, particularly the Apennine Mountains which forms a “spine” along much of the length of Italy, as well as the numerous rivers; to the north, by the time of the Allied attack on the alpine region in northern Italy, German defenses verged on complete collapse.
In the western section of the Gustav Line, the crux of the German defense centered on the heights of Monte Cassino, located near the town of Cassino and had as its prominent feature the 14th century hilltop Benedictine abbey. Monte Cassino overlooked the Liri and Rapido valleys, which the Germans believed would be the Allied route of advance to Rome, as well as the waterways, including the Rapido River, which ran across the Allied line.