On 23 September 1991, Rowan transferred from the Territorial Army to the Regular Army, thereby becoming a full-time soldier. He was made a captain (on probation) with seniority from 23 September 1984, and instantly promoted to major (on probation).[6] In November 1992, his commission was confirmed and he was granted seniority in the rank of major from 23 September 1989.[7]
Rowan was promoted to lieutenant colonel on 23 September 1996.[8] In 1999, during the Kosovo War, he was deployed to Macedonia where he was tasked with building and maintaining the refugee camps.[1] On 30 June 2004, he was promoted to colonel.[9] In 2005, during the Iraq War, he was deployed to Iraq, where he was responsible for the reconstruction of the five southern governorate. He spent roughly $150 million trying to regenerate the economy and deliver governance, infrastructure and security to the region.[1]
^"Army appointment". The Times. 20 May 2014. Retrieved 4 December 2015. To be Director General Army Medical Services in succession to Major General E B Carmichael MBE QHDS, in September 2014: Major General J F Rowan OBE QHS