The threat from Japan was the reason Air defence Artillery came into being in India in 1939 when a small number of Indian troops were initially trained to use 3-inch AA guns. This was ostensibly to counter any threat which may emerge from the Japanese advance in South East Asia. These gunners formed part of the anti-aircraft batteries of the Hong Kong and Singapore Royal Artillery (HKSRA) as the initial focus was to contain the Japanese threat in the Far East. Later the Indian troops were trained on the Bofors 40 mm L/60 guns and began to be assigned to Indian artillery formations. In the early 1940s, several anti-aircraft units and training establishments were raised throughout the country. The AA units were formed with manpower from existing Artillery establishments as also by milking some select infantry regiments. As the manpower was still inadequate to meet the ever increasing demands, direct recruitment to AA Branch of Artillery was started in July 1940 and AA and Coast Defence Wings were established at Karachi for training of Indian Officers, JCOs and NCOs in the AA techniques1.
The British War Office decided in August 1940 to create a separate AA branch of Indian Artillery on the concept of Territorial Army. This was however to be limited to Heavy AA units for static tasks and not for field formations. On 14 September 1940, One Indian AA Technical Training Battery was raised at Colaba, Bombay. It included nucleus of the first AA unit of Indian Artillery – the ‘R’ (Royal) HAA Regiment2. In January 1941, Light AA unit called the ‘U’ LAA Regiment was raised at Malir Cantt (Now in Pakistan) and was equipped with L/60 guns. In April 1941, both of these units were re-named and thus ‘R’ HAA became 1 Indian HAA Regiment IA and ‘U’ LAA became 1 Indian LAA Regiment IA. The main difference between the role of HAA and LAA Regiments was that while the HAA Regiment were for static tasks against High Altitude Bombers , the LAA units were raised for mobile role against low flying fighter aircraft. Most, if not all HAA Regiments were TA Regiments. The LAA Regiments were integral to Artillery Brigades of Infantry and Armoured Divisions, some of them being organized as Anti-Tank/ Anti-Aircraft Regiments.
By 1942, the air defence branch had grown considerably with a total of eighteen anti-aircraft regiments, of which nine were HAA Regiments and nine were Light AA Regiments. There were grouped under four AA Brigades. Besides these 18 Regiments, AAA had one Independent HAA Battery and two Independent LAA Batteries. By the end of 1944, AAA had a total of thirty three air defence artillery units making India Command the second most densely protected area- second only to Great Britain3. One interesting feature of Indian AAA was that the Infantry Divisions on standard MT(Mechanical Transport) establishment had an integral LAA Regiment with up to fifty-four light anti-aircraft guns while some had an additional composite AT/AA Regiment with two Anti Tank and Anti Aircraft Batteries each. The Indian LAA Regiments performed well during the war with Three Indian LAA Regiments being awarded with Mention-in-Desptaches during their employment in East Bengal, Assam and Rangoon. A total of three MC, one MBE and seven IDSM were awarded to AA Artillery during the Second World War4.
At the end of Second World War, a large number of AA Regiments were disbanded or converted to Field Artillery regiments or even to regular infantry Regiments. At the time of partition in 1947, in the division of assets between the two Armies, both India’s share was only two LAA Regiments with Pakistan getting two HAA and two LAA Regiments. However India was to convert one Field Artillery Regiment to HAA Regiment ( making it 2+1 AA Regiments) while Pakistan was to convert one HAA Regiment to Field Regiment and one LAA Regiment to Anti-Tank Regiment( ie 1+1 AA Regiments)5. The LAA Regiments that came to India were 26 LAA and 27 LAA Regiments, and were retained as such- 26 LAA Regiment had been raised as 2 LAA regiment in 1941. The equipment required to convert one Field Regiment to HAA Regiment was available with India but rather than convert a Field Regiment, India raised a new HAA Regiment in 1948. The reasons for not doing so are not clear. Most likely, Artillery Directorate ( the controlling Directorate for AAA also at the Army Headquarters) may not have been too keen to shed one Field Regiment hence opted for raising of a new Regiment.
The two AA Regiments that survived in to Pakistan Army were re-numbered and designated as 5 HAA Regiment(erstwhile 18 HAA Regiment) and 6 LAA Regiment(erstwhile 25 LAA Regiment).
Pakistan also got One LAA Battery which was later amalgamated into a new raising (14 LAA Battery of 13 LAA Regiment of Pakistan Army AD)6 . The two oldest AA Establishment in India, i.e. I Training Battery and ‘R’ HAA Regiment had gone to Pakistan. Of the AA Regiments, 5 Heavy Anti Aircraft Regiment which went to Pakistan was the most technical and sophisticated unit of its time, being the only one with radar controlled guns( 3.7” Radar Controlled Guns with a covering range upto 18 kms)7.
Pakistan Artillery (of which AAA was a part) was initially known as Army Group of Royal Pakistan Artillery(AGRPA) and was designated as Royal Pakistan Artillery only on March 23, 19568.
- History of Army Air Defence http://indianarmy.nic.in/Site/FormTemplete/frmTempSimple.aspx?MnId=4Fm+GZejNPYci/u/KMAV7g==&ParentID=M/DOGn6JXk49a1ugLTlLfA==History
- History of Army Air Defence. As per History of Regiment of Artillery : Pangs of Partition, the first Indian AD Unit was ‘K’ Indian Anti Aircraft Regiment raised on 1 August 1940 at Hyderabad. There is however no mention of ‘K’ AA Regiment in the History of Army Air Defence given at the Indian Army website or other sources.
- History of Army Air Defence.
- Partition of Personnel and Units of Armed Forces Fourth Meeting of Partition Council, Allocation of Armoured Corps and Infantry Units, Partition Proceedings, vol.5, p.44. http://shodhganga.inflibnet.ac.in/bitstream/10603/14220/8/08_chapter%204.pdf
Also refer to History of Artillery: Pangs of Partition http://indianarmy.nic.in/Site/FormTemplete/frmTempSimple.aspx?MnId=8Z5bhvBfqykVyUp0Sk8YRQ==&ParentID=iyOBZ+iSBXrLmgvH+uj7Iw==
- Army Air Defence, Pakistan Army https://www.pakistanarmy.gov.pk/AWPReview/TextContent.aspx?pId=22&rnd=451