In the Spring of 1941, 50th LAA Bde was split up, keeping the S/L regiments and LAA (and thus reverting to being a 'Light' AA brigade) while a new 66th AA Bde took over the HAA guns and rockets:Order of Battle of Non-Field Force Units in the United Kingdom, Part 27: AA Command, 12 May 1941, with amendments, TNA file WO 212/79.
