Paul Adrien Maurice Dirac was one of the founders of quantum theory and the author of many of its most important subsequent developments. He is numbered alongside Newton, Maxwell, Einstein and Rutherford as one of the greatest physicists of all time. He was born in Bristol on 8 August 1902 and died on 20 October 1984 in Tallahassee, Florida. On Monday 13 November 1995, after evensong, a plaque was dedicated in Westminster Abbey commemorating Paul Dirac. The simplicity and almost austere beauty of the plaque's design reflected in some ways the qualities of Dirac's unique intellect.

After graduating from Bristol University with a first class degree in engineering, Dirac stayed on to study mathematics there before obtaining a studentship in 1923 to enable him to undertake research at St John's College, Cambridge. In 1925, he became a Fellow of St John's College. In 1932, he was elected Lucasian Professor of Mathematics in the University. The Lucasian Professorship was once held by Sir Isaac Newton, and the present holder, Stephen Hawking, was present in the Abbey to give an address at the service of commemoration and the text of this address is included in this volume.

Dirac shared the 1933 Nobel Prize for Physics with Erwin Schrödinger. After retirement from the Lucasian chair in 1969, he accepted a research professorship at the Florida State University in Tallahassee. There he continued to work on fundamental physics, frequently returning to St John's College for summer visits, until shortly before his death.