Background
MacDonagh was born in Carlow, Ireland to Michael MacDonagh and Loretto Oliver, both of whom were bank officials.
MacDonagh was born in Carlow, Ireland to Michael MacDonagh and Loretto Oliver, both of whom were bank officials.
At University College Dublin he studied History and Law, but socialised more with the "literary set", graduating in 1944 with a Bachelor of Arts degree.
MacDonagh spent most of his academic career at Universities in Cambridge, Adelaide, Cork and Canberra. The family settled in Roscommon, where Oliver was initially educated by the Christian Brothers and for his secondary schooling was sent to board at Clongowes Wood College. MacDonagh was called to the Irish Bar in 1945.
From 1952 until 1964 he was a lecturer and Fellow of Street Catharine"s College, Cambridge where he was a visiting fellow in 1986 and Honorary Fellow in 1987.
Between 1963 and 1964 he was a visiting fellow at the Australian National University, where he was closely associated with Professor Keith Hancock. In 1964 he was appointed Professor of History at Flinders University on its establishment, which position he held until 1968.
He returned to Ireland as Professor of Modern History at University College, Cork in 1968, remaining until 1973. In 1970 he was a Visiting Professor at Yale University.
MacDonagh resigned from Cork in 1973 and returned to Australia as West.K. Hancock Professor in the Research School of Social Sciences at the Australian National University.
He remained there until he retired in 1990.