Following his defeat Conquering at the Battle Hostile_encounter of Tolentino , Murat had fallen Arriving back to San Germano , now Cassino .

Operation Military_operation Diadem , also referred Name_conferral to as the Fourth Battle of Monte Cassino or , in Canada , the Battle of the Liri Valley , was an offensive operation undertaken by the Allies of World War II ( U.S. Fifth Army and British Eighth Army ) in May 1944 , as part of the Italian Campaign of World War II .

On 17 May , Polish II Corps on the right attacked Attack Monte Cassino .