He was a professor of contemporary history at Leiden University, former rector of the Netherlands Institute for Advanced Study between 1995 and 2002.

At the end of 2004, Wesseling received the 21st Medal of Honor for Art and Science of the House Order of Orange from Queen Beatrix at Huis ten Bosch Palace.

On 15 April 2010, the ambassador of France presented the decorations of 'Commandeur de la Légion d'honneur ' to Wesseling.

Wesseling published widely-read studies on imperialism, the partition of Africa, French military, intellectual, and cultural history, and a biography of Charles De Gaulle.

The department was custodian of hundreds of kilometers of shelf space devoted to primary sources that were exploited by advanced students.