Soden was born in Canada but his family returned to England in 1904. In November 1914 Soden enlisted in the 8th South Staffordshire Regiment. He took private flying lessons and earned RAC certificate 3502 on 1916-09-09 and then transferred to the RFC. Between September 1916 and November 1918 he accounted for 27 enemy aircraft. He remained in the Royal Air Force when WWII ended. He received a bar to his Distinguished Flying Cross for service in Kurdistan in 1922, was promoted to Group Captain on 1 April 1939, and was commanding officer of RAF Biggin Hill from December 1940 to June 1941. When World War II ended, he went to Kenya.