Cyril Albert Clowes was born in Queensland in 1892. In 1911 he entered the Royal Military College, Duntroon. He was appointed a lieutenant in the AIF and posted to 1 Field Artillery Brigade. Clowes landed on Gallipoli on 25 April 1915 and served as a forward observation officer directing naval gunfire against Turkish positions. In January 1916 he was promoted to captain in 2 Division Artillery. He served as the Division's Trench Mortar Officer and was awarded the Military Cross. In 1918, as a major, he was awarded the Distinguished Service Order for his work at Villers Bretonneux.

Clowes returned to Australia in April 1919. Between 1920 and 1925 he served as an instructor at Duntroon. From 1926 to 1936 Clowes undertook staff, training and command duties in Brisbane, Sydney and Darwin. He was promoted to lieutenant colonel and undertook a gunnery course in England, returning to Sydney as chief instructor at the School of Artillery. He was promoted to colonel in November 1939 after assuming command of 6 Military District. In 1940 Clowes was made temporary brigadier in the Second AIF and placed in command of the Royal Australian Artillery, I Corps. He served in North Africa and in Greece. Returning to Australia in January 1942 Clowes was promoted to temporary major general and given command of 1 Division. In July he was sent to Port Moresby and given command of what became known as Milne Force. He reached Milne Bay and took up his position four days before the Japanese began their landing. His forces defeated the Japanese after a long and difficult fight in arduous conditions. Clowes was the first Allied commander to win a land victory over the Japanese during the Second World War.

He was made a Commander of the British Empire in recognition of his service. Despite this he received little support from the Australian Commander-in-Chief, General Blamey. He returned to Australia in 1943 and held no further active command posts. Clowes retired in 1949 with the rank of lieutenant general.