On 11 July 1940, at the start of the Battle, the 5th AA Division's guns were deployed as follows: •
Cardiff (Docks and industry): 12 •
Newport, Wales (Docks and industry) 4 •
Brockworth, Gloucestershire (
Gloster Aircraft Factory): 36 • Bristol: 36 •
Falmouth, Cornwall (Docks): 8 • Plymouth: 18 • Portland: 6 • Holton Heath: 8 • Southampton: 43 • Portsmouth: 44 • Bramley: 8 • Airfields: 20 • Vital points: 136 The Battle of Britain opened with the
Luftwaffe attacking shipping and coastal towns by day and bombing ports and industrial cities by night, which involved all of AA Command's divisions. In July the Luftwaffe switched to day raids in strength against ports and Midlands industry. Portland and Portsmouth were regularly raided. On 4 July, Portland was attacked by a continuous flow of
Ju 87 Stukas and
Ju 88s, lasting two and a half hours, yet none was shot down. But AA Command's shooting and techniques improved with experience. In attacks on Portsmouth on 12 August, six
Bf 109s were shot down and a searchlight detachment on the Isle of Wight shot down another with its LMG. After these preliminary skirmishes, the battle intensified from 13 August with bombing raids primarily directed against Fighter Command's airfields. Some of the greatest battles were fought on 15 August, from South Wales to the Yorkshire Coast, when the 5th AA Division was hotly engaged. On that day
Lehrgeschwader 1 (LG 1) made a heavy raid of 70–80 bombers escorted by single- and twin-engined fighters against the South Coast. No. 10 Group scrambled five fighter squadrons and action began at 17.20 over
Portland Bill. The
Stukas of IV.(St)/LG 1 and escorting
Bf 110 Zerstörers of V.(Z)/LG 1 heading for
RNAS Worthy Down were attacked out of the sun, dropped a few bombs at Portland and withdrew with heavy losses. The rest of the raid (II.(St)/LG 1) flew on to attack
RAF Middle Wallop, causing some damage, but suffering further casualties. Between the fighters and the AA guns at Portsmouth and Southampton, the
Geschwader lost 8 bombers, 4 Stukas and 13 Bf 110s, as well as many others damaged. The one-sided action was highly satisfactory for Fighter Command and the 5th AA Division. Another peak day came on 24 August, when the gunners were in action at
Swansea, Cardiff, Bristol, Portland and Bramley, with the Swansea gunners claiming hits. Then on 6 September the Luftwaffe switched its attacks from airfields to London. ==Blitz==