45th LAA Regiment was not involved in the Allied invasion of Sicily (Operation Husky), but entered the Italian Campaign as part of the British Eighth Army, commanded by Lieutenant General Sir Oliver Leese, in early 1944 when it rejoined 66th AA Bde. The brigade had been defending the Salerno landing area and airfields supporting the American Fifth Army, under Lieutenant General Mark Clark. After the breakout from the Anzio beachhead, in May 1944, it took over defence of that area, and it followed up as Fifth Army advanced to Rome and beyond.