Mathematics pervades our daily lives. It is intimately involved whenever one starts a car, switches on the television, flies on a plane, forecasts the weather, books a holiday on the internet, programmes a computer, navigates heavy traffic, analyses statistical data, or seeks a cure for a disease. Our credit cards and the nation's defence secrets are kept secure by encryption methods based on prime numbers. This book presents mathematics with a human face, celebrating the achievements of the great mathematicians in their historical context. Here you will meet time-measurers (the Mayans, Huygens), astronomers (Ptolemy, Halley), logicians (Aristotle, Russell), calculators (Napier, Babbage), geometers (Archimedes, Bolyai) and arithmeticians (Pythagoras, al-Khwarizmi), as well as such well-known figures as Geoffrey Chaucer, Christopher Wren, Napoleon, Florence Nightingale, and many more.