In France he was Aide-de-Camp to the General Officer Commanding the Australian Corps and 5th Army, his father, from 10 March 1918 to 28 February 1919.
In February 1920, he was promoted Acting Captain while attached to the 2/76th Punjabis, additionally being made Adjutant in July 1920.
[6] During the Second World War, he returned with Probyn's Horse in August 1940 and rose to become temporary second in command by April 1942, later he served on the Staff.
[citation needed] Christopher Birdwood had a strong interest in humanitarian affairs: after World War 2 he was briefly Head of the British Red Cross, and later Chairman of the Hungarian Relief Fund.
His concern about the spreading influence of communism during the "cold war" was exhibited in his speeches in the House of Lords, in becoming a Director of the Free Czechoslovak Information Service (1954–1961), his involvement in the British Tibet Society, and in numerous articles for the British press.
[citation needed] His son from his first marriage, Mark William Ogilvie Birdwood (1938–2015), succeeded to the title.