Thomas Henry Huxley PC, FRS (1825-1895) was an English biologist. He was instrumental in developing scientific education in Britain, and fought against the more extreme versions of religious tradition. He had little schooling, and taught himself almost everything he knew. Remarkably, he became perhaps the finest comparative anatomist of the second half of the nineteenth century. He worked first on invertebrates, clarifying the relationships between groups that were previously little understood. Later, he worked more on vertebrates, especially on the relationship between man and the apes. Another of his important conclusions was that birds evolved from dinosaurs, namely, small carnivorous theropods. This view is widely held today. The tendency has been for this fine anatomical work to be overshadowed by his energetic controversial activity in favour of evolution, and by his extensive public work on scientific education, both of which had significant effect on society in Britain and elsewhere.