of the Armistice with Germany. Between the wars After the war, Crocker left the army to train as a solicitor. However, he did not enjoy his new profession and returned to soldiering as an infantry officer in the Middlesex Regiment (Duke of Cambridge's Own) in the Regular Army. His rank of lieutenant was confirmed on 16 December 1920 (with seniority backdated to 20 December 1919), the same year of his marriage to Hilda Mitchell; they had a daughter, Roberta, in 1921 and a son, Wilfrid, in 1923. From 13 January 1922 Crocker was seconded to the Royal Tank Corps (later the Royal Tank Regiment) to specialise in the then new field of armoured warfare. His secondment became a permanent transfer in August 1923 (backdated to June 1919). He then went to India, where he attended the Staff College, Quetta from 1928 to 1929. Among his fellow classmates there were Douglas Gracey, Colin Gubbins, Henry Lowrie Davies, along with George Alan Vasey of the Australian Army and E. L. M. Burns of the Canadian Army, all of whom later become general officers. He was an excellent student there, with his superiors noting his "strong and independent character". He also earned a rare A-grade, which marked him as an "officer of exceptional merit and outstanding ability". After graduating from Quetta, he then held a number of both field and staff posts including brigade major to Brigadier Percy Hobart's 1st Tank Brigade and General Staff Officer Grade 1 (GSO1) to Major-General Alan Brooke when the latter was commanding the Mobile Division (later the 1st Armoured Division). He also had a period of secondment to the Royal Tank School in India from September 1925. He was promoted to captain in April 1929. Promotion in the inter-war army was slow, and Crocker's advancement was evidenced by a succession of brevet ranks: brevet major on 1 January 1935, brevet lieutenant colonel on 1 July 1936 and brevet colonel on 1 February 1938. However, his permanent rank caught up when he was promoted to colonel on 6 August 1938 (with seniority backdated to 1 February 1938). Crocker lived in Kenya from March 1938 until August 1939. By the time the Second World War began in September 1939 he was a GSO1 staff officer in Southern Command. Second World War France and England Crocker was not to remain there long, however, as on 21 April 1940 he was