His last posting was as the United Kingdom National Military Representative at Supreme Headquarters Allied Powers Europe.

Stewart was educated at St John's School, Leatherhead, where he became a Cadet Warrant Officer[1] in the CCF (RAF) Section based there.

In 1992 he moved from Leuchars to RAF Coningsby and joined the Tornado F3 Operational Conversion Unit 56 (R) Squadron as a flight commander.

In 1994 he joined the staff at 11 Group Headquarters at RAF Bentley Priory, serving on the Air Defence training desk.

In 1999 he served in the Defence Crisis Management Centre in MOD as a Kosovo briefing officer and completed a short tour within the former Directorate of Public Relations (RAF).

[7] He was elected a Fellow of the Royal Aeronautical Society (FRAeS) in 2009[8] and was appointed a Deputy Lieutenant for the East Riding of Yorkshire in 2016.