 Born in Kilkenny, Ireland, Robert Blackburn attended St. Columba's College, Rathfarnham and, in 1946, Trinity College, Dublin, where took a first-class degree in History with gold medal and was captain of the rugby XV.As a student, Blackburn was an active member of the United Nations Association, where he met his future wife, Esther Archer.Blackburn started his teaching career at Downside School in Stratton-on-the-Fosse, Somerset, moving to Merchant Taylors' School near Northwood, Middlesex, in 1954.