Robert Bertie, 1st Duke of Ancaster and Kesteven PC (20 October 1660 – 26 July 1723), styled 17th Baron Willoughby de Eresby between 1666 and 1701, and known as 4th Earl of Lindsey between 1701 and 1706, and as 1st Marquess of Lindsey between 1706 and 1715, was a British statesman and nobleman. Early life Bertie was the eldest son of Robert Bertie, 3rd Earl of Lindsey and, his second wife, the Hon. Elizabeth Wharton. Among his younger brothers were Hon. Peregrine Bertie (the Vice Chamberlain to King William III and to Queen Anne, Teller of the Exchequer), Hon. Philip Bertie (Auditor of the Duchy of Cornwall, who married Lady Elizabeth Brabazon, eldest daughter of William Brabazon, 3rd Earl of Meath), Hon. Norris Bertie (a Lt. of the Royal Navy), and Hon. Albemarle Bertie (MP who also served as Auditor of the Duchy of Cornwall. Among his sisters were Lady Jane Bertie (wife of Maj.-Gen. Edward Mathew, Governor of Grenada), Lady Caroline Bertie (second wife of Capt. George Dewar). From his father's first marriage to Mary (née Massingberd) Berkeley (widow of Hon. George Berkeley and second daughter John Massingberd, Treasurer of the East India Company), he had an elder half-sister, Lady Arabella Bertie (second wife Thomas Savage, 3rd Earl Rivers). His paternal grandparents were Montagu Bertie, 2nd Earl of Lindsey, and the former Martha Cokayne. Among his large extended family were uncles Peregrine, Richard, Vere, and Charles Bertie, and aunts Lady Elizabeth (wife of the 3rd Viscount Campden) and Lady Bridget (wife of the 1st Duke of Leeds). His mother was the only child of Philip Wharton, 4th Baron Wharton and the former Elizabeth Wandesford (daughter of Sir Rowland Wandesford of Pickhill, an attorney of the Court of Wards and Liveries). Career Lord Willoughby entered Parliament as Member of Parliament for Boston in 1685, and sat in the Loyal Parliament, from 1685 to 1687, and the Convention Parliament from 1689 to 1690. He was commissioned captain of an independent troop of horse raised to suppress the Monmouth Rebellion on 20 June 1685. In 1688, Bertie took part in the northern rising led by his kinsman, the Earl of Danby, in favour of William of Orange. He was rewarded with the chancellorship of the Duchy of Lancaster in 1689, a post which enabled him to secure a seat at Preston at the general election of 1690. In 1690, he was returned