A man of as many names as motives, Edward Bancroft is a singular figure in the history of Revolutionary America. Born in Massachusetts in 1745, Bancroft moved to England as a young man in the 1760s and began building a respectable resume as both a scientist and a man of letters. In recognition of his works in natural history, Bancroft was unanimously elected to the Royal Society, and while working to secure French aid for the American Revolution, he became a close associate of such luminaries as Benjamin Franklin, Silas Deane, and John Adams. Though lauded in his time as a staunch American patriot, when the British diplomatic archives were opened in the late nineteenth century, it was revealed that Bancroft led a secret life as a British agent acting against French and American interests. In this book, the first complete biography of Bancroft, historian Thomas Schaeper reveals the full extent of the agent's deception during the crucial years of the American Revolution. Operating under aliases, working in ciphers, and leaving coded messages in the trees of Paris' Tuileries Gardens, Bancroft filtered information from unsuspecting figures including Franklin and Deane back to his contacts in Britain, navigating a complicated web of political allegiances. Through Schaeper's keen analysis of Bancroft's correspondence and diplomatic records, this biography reveals whether Bancroft should ultimately be considered a traitor to America or a patriot to Britain.