The 101st Heavy Anti-Aircraft Regiment, Royal Artillery (101st HAA Rgt) was an air defence unit of Britain's Territorial Army raised in northern Scotland just before World War II.

Murray, OBE, MC, TD, formerly commanding officer (CO) of 4th/5th Battalion, Seaforth Highlanders, (although in his new role he only received the rank and allowances of a Major).

On the outbreak of war the battery's eight guns were the base's only land-based AA defence, though the Royal Navy estimated that at least 24 were required to protect the unarmed tankers and storeships, and the shore facilities.

Although there was as yet no early-warning radar for Scapa, 226 HAA Bty was able to engage the raiders, shooting down one, which crashed on the island of Hoy, although the decommissioned former Fleet flagship HMS Iron Duke (being used as an AA platform) was hit and had to be beached.

Forty-four HAA guns engaged, but the predictors were defeated by the bombers' erratic courses amidst the gun-flashes and low light, and none were shot down, while the Navy suffered further losses.

[30][31] 101sth HAA Regiment landed at Bombay at the beginning of July 1943 and moved to Avadi where it came under the command of 3 Indian AA Bde.

297 HAA Battery was soon detached to Madras, but returned on 10 August in time for the regiment to move back to the Bombay area.

As the force struggled forward through the Monsoon, the corps' AA gunners followed closely behind, moving east from Imphal to Tamu, and down the Kabaw Valley to meet 5th Indian Division at Kalemyo at the end of November.

[27][32][34][35][36][37] With the almost total elimination of the Japanese air force in the theatre, Fourteenth Army increasingly used its 3.7-inch HAA guns as medium artillery against ground targets.

As 11th East African Division forced its way through the Myittha Gorge to Kalewa, a troop of 101st HAA Rgt was directed by air observation post (AOP) aircraft to fire at the town.

This was at 19,400 yards (17,700 m), extreme range for a 3.7-inch gun, but the AOP pilot observed the first shot land exactly in the confluence of the Myittha and Chindwin rivers and was quickly able to correct the fire onto the nearby track junction.

Moving these heavy guns through the jungle and Paddy fields into firing positions took enormous labour, and often required extra recovery vehicles and bulldozers.

There was pressure to achieve early hits and to couple the gun up to its tractor and withdraw before the Japanese retaliated with mortar fire.

2nd Division made good progress to Shwebo in January 1945, with 226 HAA Bty providing route protection and cover for airstrips and field gun positions.

[36][43][44] The CCRA then organised a strong artillery group to support the two divisions in their assault crossing of the 2 miles (3.2 km) wide Irrawaddy River, with 101st HAA Rgt operating both its 16 x 3.7-inch and 4 x 7.2-inch equipment.

The long-range 3.7s were used for a long programme of counter-battery (CB), Interdiction and HF tasks, with half the guns capable of immediate reversion to the AA role if enemy aircraft appeared.

20th Indian Division began its crossing on 12 February 1945, supported by a corps fire programme including 'bombard' tasks from 3- to 7-inch guns at 18,400 yards (16,800 m) using AA Fuzes.

During the advance on Prome, gunners of 101st HAA Rgt fought for a while as infantry, guarding the gap between XXXIII and IV Corps.

[52][53] In June 1945, XXXIII Indian Corps was disbanded (its HQ became the basis for the new Twelfth Army) and the AA organisation in Burma was regrouped.