In 1998 he retired from the School of Oriental and African Studies, as Emeritus Professor of the History of Africa.
After studying at Cambridge University, he undertook research in Kampala before working as an oral historian in Dar es Salaam.
He was a doctoral student of Jan Vansina at University of Wisconsin–Madison, researching the history of the Bemba people in Zambia.
His doctoral field research, originally conducted in 1964–1965, ultimately resulted in the 1973 monograph A history of the Bemba.
[2] Roberts later took up a post at the School of African and Oriental Studies, taking early retirement from SOAS in 1998.