Career
Born in Dublin, Ireland, he immigrated to Canada in 1966 and has lived in Calgary, Alberta since 1974. He spent 25 years as a staff writer with the Calgary Herald, writing columns and feature stories. Brennan was a leader in the attempt by the Communications, Energy and Paperworkers Union of Canada to organize a union local and negotiate a first contract with the Calgary Herald.
When the strike ended in June 2000 with the dissolution of the union, he left to devote himself full-time to writing books and magazine articles
As a storyteller, Brennan has been heard frequently on the Canadian Broadcasting Company Radio program Daybreak Alberta.