Mark is the grandson to, Hanna Elias Hajje who arrived in Australia with his two brothers in 1890 but later changed his surname to McGuire, Hanna married in 1898, built and opened a general store at South Gundagai in 1902, the store ceased operation in 1975. At twenty-one Mark Married Julie McMinn who like himself was an athlete, they met at the Sydney Sports Ground; this year will mark their 47th wedding anniversary. In 1953 Mark was the half-mile junior champion and the NSW all school champion, with an avid interest in hobbies, he was best placed Australian at the 1974 Australian Photography Exhibition at Sydney town hall.

This man doesn't do things by half; in 1993 Mark planted 400 rose bushes in Billong Street Neutral Bay, in his garden, the nature strip, and in front of 4 different homes. Between 1996 and 2003 he won seven times the Royal Easter show championship for roses, as well as several Australian titles in the Australian Rose Championships held in Wollongong 1997. In 2003 he also won three Australian championships plus the NSW Championship held in the Hunter Valley. He is also an accredited rose judge. Mark and Julie have four children; the eldest is Mark Ashton McGuire, Professor of cardiology at Royal Prince Alfred Hospital and World Authority on irregular rhythms of the heart. Mark must have loved the life of operating under pressure and excelling.