The 4th Earl of Devonshire did not inherit his title from his father until he was 43, and by this time he had built a reputation of some notoriety. He was described by Horace Walpole as 'a patriot among the men, a gallant among the ladies', yet 'prone to take offence, ready with his sword as with his tongue, plaintiff and defendant in many lawsuits'.
He married Lady Mary Butler (1646-1710), daughter of James Butler, 1st Duke of Ormonde, in 1662 and they had four children together.
A strong supporter of the 'Glorious Revolution' of 1688, the 4th Earl was one of the 'Immortal Seven', a group of English noblemen who signed the invitation to William of Orange and his wife Mary to accept the throne in the place of Mary's father, James II.
He was a leading member of the Whig party, serving as Lord Steward for the new King, and in 1694 he was created the Duke of Devonshire and the Marquess of Hartington in recognition for his services.
By the 1680s Chatsworth had fallen into a poor state of repair, and the 4th Earl began some much-needed work on the old house. Initially, the intention was only to alter the South Front, which was taken down in 1686 and replaced with new family rooms and a magnificent State Apartment.
However, he found building so enjoyable that the East Front was soon after also rebuilt, including the Painted Hall and a long gallery (now the Library), followed by the West Front and finally the North Front.
William Talman (1650-1719) was the architect for the South and East Fronts. The West was perhaps designed by the Duke himself, working closely with his masons, and the North, with its bow front, by Thomas Archer. Decorations by Antonio Verrio, James Thornhill, and Grinling Gibbons
The new Chatsworth was finished just before the Duke died in 1707. He was succeeded by his eldest son, William.