William (Wm.) Perkins Bull was born at Downsview in 1870. His family moved to Peel County shortly after, settling just south of the Village of Brampton, within the Township of Chinguacousy. The family's well-regarded Jersey cattle farm was at Baseline and Centre Road, now Steeles and Main Street South. He graduated from Brampton High School, where he was an actor in at least one school play, The Merchant of Venice
Bull was a successful lawyer, financier, philanthropist and historian. Working as a lawyer in Toronto, he was the youngest King's Counsel in the British Empire. He invested his earnings in foreign agricultural interests, western Canada development, lumber, and oil. After spending time working in Putney Heath, London, England, and in Chicago, Bull returned to Canada in 1931.
Injured in a car accident, Perkins was encouraged by his wife to write an article about Peel County. The project quickly expanded, leading to 13 published books, and at least five more prepared manuscripts. This was accomplished by hiring a team of over 100 research staff, including True Davidson, who would go on to be the first Mayor of East York, and one of Ontario's first female mayors.
Bull’s history project also resulted in a very large collection of artifacts, archival records and artworks. In 2006, the Peel Heritage Complex (now the Peel Art Gallery, Museum and Archives) officially renamed the archives reading room the Wm. Perkins Bull Reading Room and in 2007 the Ontario Heritage Trust honoured Mr. Bull for establishing provincial historic significance.