In this 1895 survey of the life and works of James Rennell (1742-1830), the geographer and historian Clements R. Markham (1830-1916) describes him as 'the greatest geographer that Great Britain has yet produced'. The book was published in the 'Century Science Series', which narrated the lives and works of exemplars in each area of science, and Markham goes on to explain why Rennell should be the chosen representative of geography. 'He was an explorer both by sea and land, a map compiler, a physical geographer, a critical and comparative geographer, and a hydrographer.' Rennell is probably best remembered for the surveys of western Asia (also reissued in this series) in which he attempted to match modern to classical sites, but his professional career was spent as an army surveyor in India and Africa. Markham's account of Rennell's life concludes with an examination of his geographical legacy.