Question: The Indian Air Force's rank structure is based on that of the Royal Air Force, the highest rank attainable in the Indian Air Force is Marshal of the Indian Air Force, conferred by the President of India, MIAF Arjan Singh is the only officer to have achieved this rank, he was an Indian Air Force marshal who served as Chief of the Air Staff from 1964, to which year?
Context: Air Marshal Subroto Mukerjee, OBE (Bengali: সুব্রত মুখার্জী "Shubroto Mukharji") (5 March 1911 – 8 November 1960) was the first Chief of the Air Staff of the Indian Air Force (IAF).  Born in a Bengali family of repute, he was educated in India as well as England.  He joined the Royal Air Force and later was one of the first recruits of the Indian Air Force.  He had an illustrious career and had been awarded with many honours until his accidental death in 1960.  He has been called the "Father of the Indian Air Force". Field Marshal has been the highest rank in the British Army since 1736.  A five-star rank with NATO code OF-10, it is equivalent to an Admiral of the Fleet in the Royal Navy or a Marshal of the Royal Air Force in the Royal Air Force (RAF).  A Field Marshal's insignia consists of two crossed batons surrounded by yellow leaves below St Edward's Crown.  Like Marshals of the RAF and Admirals of the Fleet, Field Marshals traditionally remain officers for life, though on half-pay when not in an appointment.  The rank has been used sporadically throughout its history and was vacant during parts of the 18th and 19th centuries (when all former holders of the rank were deceased).  After the Second World War, it became standard practice to appoint the Chief of the Imperial General Staff (later renamed Chief of the General Staff) to the rank on his last day in the post.  Army officers occupying the post of Chief of the Defence Staff, the professional head of all the British Armed Forces, were usually promoted to the rank upon their appointment. Air Chief Marshal Idris Hasan Latif (b.9 June 1923) was a chief of air staff of the Indian Air Force, having served as such from 1978 to 1981.  After retirement, he has also served as the governor of the Indian state of Maharashtra (1982–85) and later as the Indian ambassador to France (till 1988).  He was the first and only Indian Muslim to become the head of the Indian Air Force, or of any Indian armed force. Marshal of the Royal Air Force (MRAF) is the highest rank in the British Royal Air Force (RAF).  In peacetime it was granted to RAF officers in the appointment of Chief of the Defence Staff (CDS), and to retired Chiefs of the Air Staff (CAS), who were promoted to it on their last day of service.  While surviving marshals of the RAF retain the rank for life, the highest rank to which officers on active service are promoted is now air chief marshal.  Although general promotions to Marshal of the Royal Air Force have been discontinued since the British defence cuts of the 1990s, further promotions to the rank may still be made in wartime, for members of the Royal Family and certain very senior RAF air officers in peacetime at the discretion of the monarch; all such promotions in peacetime are only honorary, however.  In 2012, Charles, Prince of Wales was promoted to the rank while in 2014 Lord Stirrup, who had served as Chief of the Air Staff and Chief of the Defence Staff for over seven years, was also promoted. The Eastern Air Command is one of the five operational commands of the Indian Air Force.  Currently headquartered in Shillong in Meghalaya.  Named No 1 Operational Group at the time of its inception, 27 May 1958, it was based at Ranikutir in Kolkata as a part of the Govt's increasing emphasis on defence of the eastern borders.  The Operational Group was upgraded as Command on 1 December 1959 with headquarters at Fort William, Kolkata and Air Vice Marshal KL Sondhi as the first AOC-in-C of the Eastern Command Indian Air Force#Rank structure.  After the 1962 Indo-Chinese War, The decision was made to raise a full-fledged command at Shillong.  The area of responsibility of the command now covers 11 states, and is bound by the international boundaries of Nepal, Bhutan, China, Myanmar and Bangladesh incorporating 6300 km of common border.  Eastern Air Command now has permanent airbases at Chabua, Guwahati, Bagdogra, Barrackpore, Hasimara, Jorhat, Kalaikunda and Tezpur with forward airbases at Agartala, Kolkata, Panagarh and Shillong.  Eastern Air Command consists of Air Defence squadrons consisting of the MiG-21 and Ground attack squadrons consisting of the MiG-27.  It holds the motto Samareshu Parakramaha ("Lit: Valour in battle"), The following is a list of Royal Air Force air chief marshals.  The rank of air chief marshal is a four-star officer rank and currently the highest rank to which RAF officers may be promoted to in a professional capacity.  Throughout the history of the RAF there have been 140 RAF officers promoted to air chief marshal and at present two RAF officers hold the rank in an active capacity, namely the Chief of the Air Staff (the only dedicated RAF 4-star post) and the Chief of the Defence Staff (the only tri-service 4-star post currently occupied by an air chief marshal). The Indian Air Force's rank structure is based on that of the Royal Air Force.  The highest rank attainable in the Indian Air Force is Marshal of the Indian Air Force, conferred by the President of India after exceptional service during wartime.  MIAF Arjan Singh is the only officer to have achieved this rank.  The head of the Indian Air Force is the Chief of the Air Staff, who holds the rank of Air Chief Marshal.  The current Chief of the Air Staff is Air Chief Marshal Birender Singh Dhanoa, appointed on 31 December 2016, following the retirement of Air Chief Marshal Arup Raha. The following is a list of Australians who have attained air marshal rank within the Royal Australian Air Force (RAAF); that is, service personnel who have held the rank of air chief marshal (four-star rank), air marshal (three-star rank) or air vice marshal (two-star rank).  The Royal Australian Air Force was established in 1921 as a separate branch of the Australian military forces.  The service was modelled after the Royal Air Force—formed three years earlier—and adopted the same ranking system.  Richard Williams, regarded as the "father" of the Royal Australian Air Force, was the service's first member to obtain air-officer rank on being promoted to air commodore (one-star rank) in 1927; he went on to become the first air vice marshal (1935) and air marshal (1940).  In 1965, Sir Frederick Scherger became the first officer to be advanced to air chief marshal, one of only four members of the Royal Australian Air Force to obtain this rank as of June 2014.  A further nineteen individuals have reached air marshal in the RAAF and 126 air vice marshal; seven officers have retired with the honorary rank of air vice marshal. Chief of the Air Staff is the commander and the highest-ranking officer of the Indian Air Force.  The position is abbreviated as CAS in the Indian Air Force cables & communication, and is usually held by a four-star officer of the rank Air Chief Marshal.  The current CAS is Air Chief Marshal Birender Singh Dhanoa who took office on 31 December 2016, following the retirement of Air Chief Marshal Arup Raha. Marshal of the Indian Air Force Arjan Singh, DFC (16 April 1919 – 16 September 2017) was an Indian Air Force marshal who served as Chief of the Air Staff from 1964 to 1969.  For his distinguished service in commanding the IAF during the Indo-Pakistani War of 1965, he was awarded the Padma Vibhushan and in 1966 became the first IAF officer to be promoted to air chief marshal.  After retiring from the IAF, he served as a diplomat, politician and advisor to the Indian government.  He was Lieutenant Governor of Delhi from 1989 to 1990.  In 2002, he became the first and only officer of the Indian Air Force to be promoted to five-star rank as Marshal of the Indian Air Force, equal to the army rank of Field Marshal.
Answer: 1969