Complex sentence: The 11th Wing was first constituted as the 11th Observation Group 1 October 1933, and redesignated as the 11 Bombardment Group (Medium) on 1 January 1938, but was not activated until 1 February 1940.
Split into simpler sentences: The 11th Wing was first established as the 11th Observation Group 1 October 1933. The group was redesignated as the 11 Bombardment Group (Medium) on 1 January 1938, although not activated until 1 February 1940.