The 6615th Ranger Force was formed specially for use in the Anzio landings (codenamed Operation Shingle). The 1st, 3rd, and 4th Ranger Battalions, the 509th Parachute Infantry Battalion, and several other units were molded into a temporary regiment given the name "6615th Ranger Force." Colonel William Orlando Darby, the former commanding officer (CO) of the famous 1st Ranger Battalion, became the regimental commanding officer. Lieutenant Colonel Hermann Dammer served as the regimental executive officer (XO).