In 1945 they moved to Bridport, Dorset, and in the following year John entered Grammar School, where he began to learn French and Latin.
There he spent three years studying Arabic, with some courses in Islamic history and culture with professors such as Bernard Lewis, Peter Holt and Ann Lambton, while his primary teacher of the language was Marsden Jones.
By then he had already begun research into historical aspects of Islam in Africa, beginning with interest in the Timbuktu tradition and the Songhay empire.
While in Ghana he began teaching a year-long undergraduate course in the history of the Islamic empire from the life of the Prophet through to the 16th century in North Africa.
In his first years there he also worked on his PhD thesis, editing and translating with commentaries and introduction the replies of al-Maghili to questions put to him by Askiya al-hajj Muhammad of Songhay, using manuscripts Hunwick had first started studying when at the University of Ibadan.
In 1981 he began his tenure at Northwestern University, holding a joint appointment in the Department of Religion and taught the social and intellectual history of Islamic Africa.
He is former director of the Fontes Historiae Africanae project of the International Academic Union, and has received awards from the National Endowment for the Humanities, the American Council of Learned Societies, and the Fulbright Commission.