Terry was born in Gillingham and was educated at the town’s Grammar School. He read Geography at St Catharine’s College, Cambridge, and subsequently pursued a research career on the Intelligence Staff of the Ministry of Defence in Whitehall. He joined the KAS when approaching retirement and began to build up his knowledge of the history and archaeology of Kent by taking advantage of the wide range of study courses then available in the County. In 1999 he was appointed Hon. Editor of the Society.
With his Geography background he was actively involved in encouraging the KAS to sponsor the publication of An Historical Atlas of Kent which he co-edited and to which he contributed various chapters. His main research interest is the changing pattern of Kent’s population distribution since Roman times.