The 1st Anti Aircraft Battery RCA was mobilized in September 1939 at Montreal as 1st Medium Battery RCA CASF. Unit arrived in the UK 27 September 1941, and participated in the air defense of England until March 1944. The Battery landed in Normandy in August 1944 and served throughout the Northwest Europe Campaign as part of the First Canadian Army. The 1 HAA was disbanded on 07 September 1945.
