My father, Heinz-Peter King, who has died aged 94, was a senior lecturer at St Andrews University and a historian of medieval ecclesiastical matters.

His books included The Finances of the Cistercian Order in the Fourteenth Century (1985) and Western Monasticism: A History of the Monastic Movement in the Latin Church (1999).

Peter was born in Berlin, Germany, as the only child of a Jewish couple, Ludwig Königsberger, a lawyer, and his wife, Alice (nee Licht). His early life in the Weimar Republic was one of privilege, but when Nazi racial laws disbarred Ludwig from legal practice in 1933 the family left Berlin, arriving in London the day before Peter’s fourth birthday and eventually changing their surname to King.

The new family home in Hendon, north-west London, was destroyed by German bombing in 1940 and Peter, who was by then attending Highgate school, was evacuated with his fellow pupils to Westward Ho! in Devon.

After Ludwig’s return from internment and war service with the Pioneer Corps, the family at first lived in a one-bedroomed flat in Kilburn. By 1954, reparations payments from the German government finally brought them financial stability and a new home in Cricklewood.

Peter excelled at Highgate school, particularly in history, and after being exempted from national service because of his flat feet he went on to study medieval history at the London School of Economics, graduating in 1954 with a master’s degree.

His first job was at the Institute of Historical Research, helping to write the Victoria County History series on the history of every county in England. At the institute he worked alongside Hugh Trevor-Roper and also met a trainee librarian, Christine Key, whom he married in 1960. In 1963 the couple moved to Dublin, where Peter became a lecturer in medieval history at University College and Christine worked at the Trinity College library.

In 1966 Peter took up a post as senior lecturer in medieval history at the University of St Andrews, where he taught until retirement in 1986. While there he wrote a number of books, including The Tax Book of the Cistercian Order (with Arne Odd Johnsen, 1979). He also contributed to the Cambridge Companion to the Cistercian Order (2012) and was elected as a fellow of the Society of Antiquaries of London in 1978.

After his retirement Peter continued to work voluntarily for St Andrews including as a cataloguer of the George Hay Forbes collection. Having converted to Catholicism during his student days, he attended St James’ church in St Andrews, and wrote a history of the building and parish. Committed to ecumenicism, he regularly contributed to efforts to foster connections between faith groups in St Andrews.

After Christine’s death in 2013, Peter began a PhD at the university. With its completion in 2018 at the age of 89, he became the oldest graduate in its 600-year history.

He is survived by his children, Stephen and me.