The Globe and Mail has a fine obituary for James Eayrs, who in his day was pretty much the leading Canadian political scientist and prominent media commentator, as well as being the one that historians all seemed to read on political history.
A prolific and influential author in the field of 20th-century Canadian foreign policy and diplomacy, his multi-volume In Defence of Canada won the Governor-General's Award for Non-Fiction in 1965. He was co-editor, along with Robert Spencer, of the International Journal for 25 years. In recognition of his remarkable academic work he received numerous grants, lectureships and fellowships both in Canada and abroad, including the prestigious Canada Council Molson Prize in 1984. He was elected a fellow of the Royal Society of Canada, and in 1985 was appointed an officer of the Order of Canada.
In later life, Wayne Roberts emphasized his social activist and food policy studies and campaigns more than his historical work, and he was long prominent in left wing circles around Toronto. But at the start he was part of the new labour history community that pioneered ways to emphasize the social history of labour and working people over the institutional study of labour organizations. Here's a Wikipedia entry.
