Robert Bertie 1660-1723
Robert BERTIE, 1st Duke of Ancaster and Kesteven 1660-1723
Eldest son of Robert Bertie, 3rd Earl of Lindsey, from whom he inherited the earldom and family estates in 1701. Having supported William III at an early stage, he was made Chancellor of the Duchy of Lancaster in 1689; he was MP for Boston 1685-90, when he entered the House of Lords as Baron Willoughby de Eresby. He became Lord Chamberlain on his father's death and was variously involved in government business in the early 18th century; he was made Marquis of Lindsey in 1706, and Duke of Ancaster and Kesteven in 1715, when he employed Sir John Vanbrugh to redevelop his seat at Grimsthorpe Castle, Lincolnshire.
Bertie used an engraved armorial bookplate, dated 1705 (Franks *64). The extent of his library is not known; his principal heir, and inheritor of the dukedom, was his son Peregrine.