The greatest divergence of opinion in the three-month controversy over the Regency in 1788–9 was within the opposition party itself. Dr Derry shows that this political crisis was the first stage in the break-up of the old Whig party, which was finally precipitated by the disputes over the French Revolution. His book is a study of the effects of George III's madness upon Fox, Burke and the Whigs. Dr Derry sketches in the general political background, giving character studies of Pitt and Fox. He discusses the constitutional problems of a Regency and the medical diagnoses of the King's doctors, a major factor governing political conduct since so much depended on the condition of the King.