Sir Charles Lyell (1797–1875) was one of the most renowned geologists of the nineteenth century. He was awarded the Copley Medal by the Royal Society in 1858 and the Wollaston Medal by the Geological Society of London in 1866 for his contributions to geology. Lyell's most important contribution to modern geology was his refining and popularising the geological concept of uniformitarianism, the idea that the earth has been formed through slow-acting geological forces. This biography, first published in 1881 and edited by his sister-in-law K. M. Lyell provides an intimate view of Lyell's personal and professional life through the inclusion of his correspondence with family, friends and academic peers. His changing ideas concerning the validity of the theory of natural selection and other geological ideas are also examined through the inclusion of extracts from his private journal.