Gowrie was born in Windsor, Berkshire, England, into a minor aristocratic family. He joined a voluntary Yeomanry unit at the age of 17, and then enlisted in the regular army at the age of 19. Gowrie fought in the Sudan during the Mahdist Revolt, and was awarded the Victoria Cross for saving a wounded Egyptian soldier. He later served in the Somaliland campaign and as an aide-de-camp to the Lord Lieutenant of Ireland. During the First World War, Gowrie commanded units in the Gallipoli campaign and on the Western Front, winning several further honours. He finished his military career with the rank of brigadier-general.