Battalion at Oxford for the remainder of the war. Professional life, cricket and India After resigning his Army commission in May 1919, Johnstone returned to Pembroke College, Cambridge, studying for a law degree. He graduated in 1920 having been credited with four terms study due to his war service. He played cricket for the University side, making his first-class cricket debut for the team in May 1919 against the Australian Imperial Forces at Fenner's. He won a Blue in both cricket and golf, captaining the Cambridge side to an unexpected victory in the University golf match, and made his Kent First XI debut in 1919 against Hampshire. After graduating Johnstone was employed by a liquor manufacturer in Calcutta and then for a number of years by Burmah Shell in Madras as a manager. He spent the 1925 summer in England, played 12 times during the season for Kent and was awarded his county cap. Further appearances for the county followed in 1929, but the majority of his cricket was played in India playing particularly for the Europeans and for Madras Cricket Club. He captained Madras in the inaugural Ranji Trophy in 1934 was captain in 1940/41 when the team were runners-up in the competition, losing to Bombay in the final, and played regularly in Madras Presidency Matches from 1925/26 to 1947/48, captaining the Europeans side for much of the period. When Madras entered the Madras League for the first time in 1939 Johnstone was the captain and a key player on the team and captained the Madras side throughout the period. Johnstone played both against Marylebone Cricket Club when it toured Madras in 1926/27 and for the club in five matches as well as for other teams on occasion. He remained in the Reserve of Officers until 1937. Johnstone is credited as a significant factor in the development of cricket in Madras. He has been described as having played a "pioneering role" in the growth of the sport who was able to provide talented young players with employment in Burmah Shell, providing them with the opportunity to play cricket with a stable income behind them. Players such as M. J. Gopalan, who became a double Indian international in both cricket and hockey, benefited in this way. Johnstone was President of Madras Cricket Club in 1947 towards the end of his playing career. As a player he was described as "an