Iven Giffard Mackay - Between The Wars

Between The Wars

After the end of the war, Mackay took advantage of Brigadier General George Merrick Long's education scheme to study physics at Emmanuel College at the University of Cambridge under Ernest Rutherford. His first child, Jean Margaret, was born in Cambridge in 1919. Iven and Marjorie later had two more children, a son, Iven John, born in Sydney in 1920, and another daughter, Alison, born in Sydney in 1930.

They returned to Australia aboard the transport Mantua, which reached Sydney on 19 February 1920. With the war over, the AIF was demobilised, and Mackay's appointment to the AIF was terminated on 4 April 1920. Mackay returned to lecturing in physics at the University of Sydney. Between 1922 and 1932 he was student adviser. From 1925 he was also faculty secretary. From 1932 to 1940, Mackay also worked evenings as a Commonwealth Film Appeals Censor.

In 1933, he was appointed headmaster of Cranbrook School Sydney. The school's constitution was changed to allow Mackay, a Presbyterian, to hold the post. As a result of a case of mistaken identity following the death of Major General James Alexander Kenneth Mackay in 1935, Mackay got to read his own obituary in The Times, entitled "Athlete, Soldier and Headmaster". He normally avoided publicity, but this incident brought him to national attention.

Mackay remained active in the Militia throughout the inter-war period. He held the rank of honorary Brigadier General from 21 January 1920 to late June 1937 when he was promoted to that rank substantively. He commanded the 9th Infantry Brigade from 1 July 1920 to 30 April 1921, the 8th Infantry Brigade from 1 May 1921 to 30 April 1926 and the 5th Infantry Brigade from 1 May 1930 to 31 December 1932. On 24 March 1937, he took command of the 2nd Division. He was promoted to major general on 1 July 1937. Mackay was one of only four Militia officers to be substantively promoted to that rank between 1929 and 1939.

His term of office at Cranbrook ended acrimoniously after Justice Kenneth Street and others blamed Mackay for the school's slow recovery from the Great Depression, and the school council voted to remove him on 25 October 1939. Mackay was given twelve month's notice. When, in December 1939, Mackay's daughter Jean married Lieutenant W. H. Travers, the grandson of Major General William Holmes, the reception was held at Cranbrook.