The town is home to the national operational headquarters of the Luxembourgish Army at the Haerebierg Military Centre (located on the hill Herrenberg) and the National Museum of Military History, reflecting Diekirch's pivotal role in the famous Battle of the Bulge, called by the Germans "Rundstedt-Offensive", a major battle of World War II. It was here that the river Sauer was crossed on the night of January 18, 1945, by the US 5th Infantry division.