This is the only comprehensive and authoritative modern biography of Charles, second Earl Grey, a leading figure in the Whig party from the 1780s to the 1830s, and the Prime Minister who passed the Great Reform Act of 1832. Smith here portrays Grey as chiefly responsible for guiding the country through a period of threatened revolution and maintaining the continuity of its political institutions. Drawing on an extensive range of historical sources, some of them previously unpublished, this study re-evaluates Grey's career and achievements in light of modern scholarship, and provides a unique insight into his complex and troubled personality.