 In June 1940, the Royal Artillery's AA Regiments were redesignated Heavy AA (HAA) to distinguish them from the new Light AA (LAA) regiments being formed.By the start of the Battle of Britain, in July 1940, the number of HAA guns deployed in the Liverpool GDA had reached 52.The first "Luftwaffe" attack on Liverpool came on 28 August, and there were a number of raids thereafter.