Israel Halperin, CM, mathematician, human rights activist (born 5 January 1911 in Montreal, QC; died 8 March 2007 in Toronto, ON). Halperin advanced mathematical knowledge in the fields of operator algebras and operator theory. (See also Mathematics.) He became embroiled in the Gouzenko Affair in 1946 when he was accused of being an informant for the Soviet Union. After this ordeal, Halperin returned to his post as a professor at Queen’s University, later also teaching at the University of Toronto. Beginning in the 1970s, he created letter-writing campaigns that aimed to end human rights abuses and free political prisoners.