His greatest achievements were the four large volumes, Voltaire en son temps, published by the Voltaire Foundation between 1985 and 1994.

Voltaire Foundation, Oxford, 2001.

Oxford, Voltaire Foundation, 1980.

Oxford, Voltaire Foundation, 1982.

Oxford, Voltaire Foundation, 1993.

Following Besterman's death on 10 November 1976, the Voltaire Foundation was vested permanently in the University of Oxford.

Since its inception the Voltaire Foundation has been awarded many awards in recognition of the project.

Oxford: The Voltaire Foundation, 1981.

Oxford : Voltaire Foundation at the Taylor Institution, 1994.

Oxford: Voltaire Foundation, 1997.