Percy Shelley was a poet, literary theorist, translator, political thinker, pamphleteer, and social activist. A voluminous reader and bold experimenter, he is worth consulting on any of the multifarious topics he addressed, from vegetarianism to war. He is closely associated with reform because he helped define its principles and practices, intervening in debates about the redistribution of wealth in Britain between 1810 and 1822 and the role played by religion in legitimizing tyranny. His conduct was as distinctive as his thinking, in the public as well as the domestic sphere, helping to create a body of legend around him and his circle. Shelley offers compelling evidence of the upper-class radical and of the political poet with lyrical and philosophical gifts.

Percy Bysshe Shelley was the grandson of Bysshe Shelley, a wealthy Whig landowner created baronet in 1806 as a result of his connections to the duke of Norfolk. Percy's father, Timothy...