On this day, 81 years ago, January 15, 1944 (December 20, 1943 in the lunar calendar), the Allies marched towards Rome in Italy. In July 1943, the Allied landings on Sicily forced the collapse of Mussolini's fascist government. After seizing Sicily on August 17, they decided to continue attacking mainland Italy. The ground attack force was the 15th Army Group commanded by British General Alexander, which included the British 8th Army Group in Montgomery and the U.S. 5th Army Group under Clark. In the early morning of September 3, the British Eighth Army crossed the narrow Strait of Messina from Sicily, landed on the Apennine Peninsula in Italy, and rapidly advanced towards southern Italy. On September 8, the BBC broadcast an official announcement of Italy's surrender. In the early morning of September 9, the U.S. Fifth Army commanded by Clark landed in Salerno Bay. The German army, already on alert, immediately disarmed 800,000 Italian troops, arrested a large number of Italian officers, and occupied Rome on September 10, taking control of mainland Italy as far south as Naples. On September 13, Hitler sent SS commandos to rescue Mussolini, who was imprisoned in the Hilltop Hotel of Grand Sasso. Then, with Hitler's support, Mussolini established the puppet government of the "Italian Social Republic" in northern Italy. In January 1944, in order to break the deadlock and speed up the battle, the 15th Army Group commanded by Alexander decided to carry out landing operations in the small town of Anzio in southern Rome while strengthening the frontal attack, breaking through the German defense line from behind. Rome was liberated on June 4, 1944.