Which event took place first, Operation Undertone or the Battle of Leyte?
Operation Undertone Operation Undertone was a large assault by the U.S. Seventh and French 1st Armies of the U.S. Sixth Army Group as part of the Allied invasion of Germany in March 1945 during World War II.
Operation Bolero Operation Bolero was the commonly used reference for the code name of the United States military troop buildup in the United Kingdom during World War II in preparation for the initial cross-channel invasion plan known as Operation Roundup, to be implemented in mid-1943, or for its lesser contingency alternative, Operation Sledgehammer, to be executed in the fall of 1942 in the event of German setbacks or to ease Axis pressure on the Eastern Front. ("Bolero" was the code name used in official communications to stand in for "United Kingdom" when describing the theater or movements.) What later became the Bolero plan – the buildup of a strategic air force in Great Britain in preparation for Roundup – was first submitted by Commanding General of the U.S. Army Air Forces, Henry H. Arnold, to General George Marshall, the U.S. Army Chief of Staff, on April 12, 1942, and set in motion a huge movement of men and material that laid the groundwork for Operation Overlord.