From 1941 to 1945, Rowley served with
5/10th Baluch Regiment of the
British Indian Army in India and Burma. Rowley "developed notable leadership qualities", fighting in Burma and southeast Asia, and was "just the sort of man the Secret Intelligence Service (SIS), or MI6, was looking for", according to his obituary in
The Times. Rowley joined the Secret Intelligence Service (SIS) in 1948. In 1963, Rowley completed a three-year secondment with the
Australian Secret Intelligence Service (ASIS), and became responsible for intelligence gathering in Rhodesia, under
John Debenham Taylor. ==Honours==