In 1948 Montgomery recommended Crocker to be his successor as CIGS, but the then Prime Minister, Clement Attlee, appointed the better-known and more senior General Sir William Slim, who had commanded the Fourteenth Army in the Burma Campaign during the war, much to Montgomery's annoyance. Crocker's most important postwar contribution was to write the training manuals that laid down the British Army's doctrine of armoured warfare through the years of the Cold War. Crocker held a number of honorary appointments throughout the postwar years, including Aide de Camp to the King (1948 to 1951), Colonel Commandant of the Royal Tank Regiment (1949), and Honorary Colonel of the Royal Armoured Corps (1949).