This biography provides a fresh look at the life and work of an outstanding radical figure in 17th century England. Sir Henry Vane the Younger was an idealist, both politically and theologically. A youthful Governor of Massachusetts, he became the leading Parliamentarian in England during the Commonwealth period. He led attempts to introduce a written constitution based on the supremacy of Parliament and he campaigned for religious toleration. After the Restoration Charles II declared him to be "too dangerous a man to let live".