One of two sons, his father was an electrical engineer and a celebrated artist, and his mother the former Margaret Irving.

After management training at Imperial Oil and at the headquarters of Bata International in Toronto, Markwell began his career in insurance with the Phoenix Assurance Company of Canada (later Phoenix Continental) in 1968, where he rose through various positions to become vice-president of Marketing.

Markwell left the Phoenix briefly in 1973 to assume the position of Executive Assistant to the Deputy Minister of Consumer and Commercial Relations.

In 1985 he moved to Xerox Financial Crum & Forster, to become its president and chief operating officer.

[3] and in 1995 he formed Markwell & Associates a family-owned consultancy serving financial services companies in Canada and around the world.