The Natural History, the life work of the English naturalist and artist Mark Catesby (1682-1749), the most important precursor of Audubon, was twenty years in the making, from 1729 to 1749. It was the first comprehensive study of the flora and fauna of the eastern seaboard of North America, and its beautifully finished, often striking images remained an indispensable reference source throughout the century of its publication. Published here for the first time are the original watercolors from which Catesby prepared the etchings which accompanied his published volumes. Having been stored away from the light between the pages of a unique copy of the book in the Royal Library at Windsor, which King George III bought in 1768, they are wonderfully fresh, and communicate all the enthusiasm of the pioneer naturalist amazed by the colors and variety of the new species of birds, fish, mammals, reptiles, insects and plants he was documenting (some of them now extinct). The watercolors have recently undergone conservation at the Royal Library and selections are being exhibited at several international venues. The conservation has brought to light many new drawings illustrating Catesby's working methods, and Henrietta McBurney's research sheds valuable new light on Catesby and the composition of his epochal Natural History.