Matthew Sleap is a historical geographer with a particular interest in the impact of decolonisation on communities in Africa, South America and, latterly, India. His background in the military services was in developing information systems to support better understanding of deployments by the armed forces in unfamiliar theatres. He specialised in providing software systems for influence operations to assist communities in deployments that are alienated both physically from the property and land they depend on and from their way of life. The aim was to better prepare people for the prevailing situation before embarkation to be ready to support and defend the rule of law and order. He has also led expeditions that combine academic research and exploration of remote areas. His expeditions ranging from Guyana, the Maya Mountains of Belize to the Jotunheim, DovreFjell and Hardangervidda glacier in Norway have sought to develop better understanding of people and environments. He led sailing expeditions to widely spread areas from the Caribbean to the Baltic and Mediterranean. He is a Church Warden of Frimley Parish where Colonel John Pennycuick is buried. He is married with two daughters and five grandchildren.