Katherine Villiers, Duchess of Buckingham

Katherine MacDonnell, Marchioness of Antrim, 18th Baroness de Ros of Helmsley (néeManners; died 1649), better known by her first marriage as Katherine, Duchess of Buckingham, was an English aristocrat. The daughter and heiress of Francis Manners, 6th Earl of Rutland, she was known as the richest woman in Britain outside of the royal family. She married first George Villiers, 1st Duke of Buckingham, the favourite, and possibly lover, of King James I of England; and secondly, she married the Irish peerRandal MacDonnell, 1st Marquess of Antrim.