John Crocker

General Sir John Tredinnick Crocker GCB, KBE, DSO, MC (4 January 1896 – 9 March 1963) was a British Army officer and corps commander during the Second World War.

First World War
Upon the outbreak of the First World War Crocker enlisted as a private in the Artists' Rifles, a training corps for officers, before joining the Machine Gun Corps (MGC) as an officer. He had a distinguished career in the war and won both the Distinguished Service Order and Military Cross with 174th Machine Gun Company of 59th Division in France.

Between the Wars
After the armistice, Crocker left the army to train as a solicitor. However, he did not enjoy his new profession and decided to return to soldiering. After a short period as an infantry officer in the Middlesex Regiment, Crocker specialised in the then new field of armoured warfare and joined the Royal Tank Corps in 1923. He held a number of both field and staff posts including Brigade Major to Percy Hobart and GSO1 to Alan Brooke when the latter was commanding the Mobile Division. By the time the Second World War began he was GSO1 Staff Officer in Southern Command.

Second World War
In April 1940 he was appointed to command of 3rd Armoured Brigade in the 1st Armoured Division in France. Crocker's brigade, like much of the British Expeditionary Force (BEF), was virtually destroyed in the Battle of France in 1940. Landed at Cherbourg as the rest of the BEF retreated to Dunkirk, 1st Armoured Division unsuccessfully attacked the German bridgeheads over the River Somme before returning to Cherbourg where the remnants (including the brigade's last 13 tanks) were evacuated.

Back in Britain, Crocker was given command of the new 6th Armoured Division in September 1940, of XI Corps in East Anglia in March 1942 and then of IX Corps in September 1942, before again being sent overseas in 1943, this time to Tunisia. Crocker showed impatience at Fondouk Pass on 8 April 1943 when his attempt to push 6th Armoured and 34th US Infantry Division though a gap ran onto hastily-prepared German defences. He was wounded in a training accident, during a demonstration of a PIAT anti-tank weapon, shortly before the final battle for Tunis and saw no further action in North Africa. He did, however, create something of a controversy when he criticised the performance of American troops to the press.

On his return to service in August 1943 he was given command of I Corps, part of Miles Dempsey's Second Army, training for Operation Overlord, the Allied invasion of France. Despite Crocker's background in armoured warfare, I Corps was predominantly an infantry formation, but General (later Field Marshal) Montgomery, commanding 21st Army Group, had confidence in his organisational skills and assigned I Corps the difficult task of capturing Caen. On D-Day Crocker had a larger task than any other corps commander: he had to control two landing beaches (Juno and Sword) and an airborne assault. The fact that in spite of inevitable mishaps the landings went so well was a testimony to Crocker's planning.

However, Caen did not fall on D-Day as planned, and Crocker's corps took part in the bloody two-month Battle for Caen, including Operation Charnwood. Coming under command of Lieutenant-General Harry Crerar's First Canadian Army in August 1944, I Corps drove to the Seine and then took part in the unglamorous mopping up operations along the French and Belgian coastline. When the final German surrender came in May 1945, I Corps was still on the south bank of the River Maas facing the German 25th Army. Crocker's only son Wilfrid Crocker, a tank officer in the 5th Royal Inniskilling Dragoon Guards, was killed on 20 October 1944 fighting in Holland.

Later life
In 1945 he became General Officer Commanding-in-Chief Southern Command, then in 1947 he moved on to be Commander in Chief Middle East Land Forces and in 1950 his career culminating in him becoming Adjutant-General to the Forces, before retiring in 1953. In 1949 Montgomery recommended Crocker to be his successor as Chief of the Imperial General Staff, but the prime minister, Clement Attlee, appointed the better-known Sir William Slim. 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.

After retiring he became Vice-Chairman of the Imperial War Graves Commission and Lord Lieutenant of Middlesex.