After completing his graduate work at the University of Toronto in 1960, Henry taught English literature as a specialist in the medieval and modern periods for 36 years. From 1960 to 1962 he taught at the University of Munich in Germany. From there he went to the University of Alberta in Edmonton, and from 1964 -1966 he was Canadian Aid Professor at the University of the West Indies in Trinidad. In 1966, he joined the English faculty at Sir George Williams, now Concordia,University, in Montreal, where he established the Creative Writing program that is still flourishing. He became a Full Professor in 1976, and was promoted toDistinguished Emeritus Professor upon his retirement in 1996.
His versatility as a writer is evident even in a partial list of them: 18 volumes of poetry; 6 books of plays, both for adults and for young audiences; translations from the works of Bauer, Huchel,Ibsen, Mrozek, Dorst and Sophocles; fiction and non-fiction; a book on Canada; a Festschrift for Irving Layton; and two anthologies of plays for high schools. His work has been translated into more than a dozen languages.