Trevor Hearl was one of the main authorities on the history of St. Helena. He amassed a vast collection of books and papers relating to the island which were received by the Bodleian Library following his death in 2007.

Hearl first visited St. Helena in 1969 as an education advisor when he was working as a lecturer at St. Paul's College, Cheltenham. This visit led to the formation of The Cheltenham-St. Helena Link, an organisation which linked the Cheltenham Colleges of St. Mary and St. Paul, and the University of Bristol School of Education, with the Education Department of St. Helena. The Link (which developed into The St. Helena Link) had been established at the request of the island's government to assist in its programme of teacher education and training.

Hearl's interest in St. Helena continued after his retirement from teaching and in 1990 he re-published, at his own expense, Philip Gosse's history of the island ( St. Helena, 1502-1938).

Trevor Hearl’s main writings have been published in St. Helena Britannica: Studies in South Atlantic Island History, edited by A. H. Schulenburg (London: Society of Friends of St. Helena: distributor Miles Apart, 2013).

These biographical notes have been taken from the Spring 2007 issue of The Wirebird (the journal of the Friends of St. Helena) which was dedicated to Hearl.