Which Army rank was Winston Churchill temporarily promoted to during the First World War?

Sir Winston Leonard Spencer Churchill (30 November 1874 – 24 January 1965) was a British statesman who served as Prime Minister of the United Kingdom from 1940 to 1945, during the Second World War, and again from 1951 to 1955.

On 25 November 1915, Churchill resigned from the government, although he remained an Member of Parliament. Asquith rejected his request to be appointed Governor-General of British East Africa.

Churchill decided to join the Army and was attached to the 2nd Grenadier Guards, on the Western Front. In January 1916, he was temporarily promoted to lieutenant-colonel and given command of the 6th Royal Scots Fusiliers. After a period of training, the battalion was moved to a sector of the Belgian Front near Ploegsteert. For over three months, they faced continual shelling although no German offensive. Churchill narrowly escaped death when, during a visit by his staff officer cousin the 9th Duke of Marlborough, a large piece of shrapnel fell between them.

In May, the 6th Royal Scots Fusiliers were merged into the 15th Division. Churchill did not request a new command, instead securing permission to leave active service. His temporary promotion ended on 16 May, when he returned to the rank of major.