Philippa de Vere, Duchess of Ireland

Philippa de Coucy, Countess of Oxford, Duchess of Ireland, was a first cousin of King Richard II of England and the wife of Robert de Vere, 9th Earl of Oxford, Marquess of Dublin, Duke of Ireland. Born at Eltham Palace shortly before 18 April 1367, she was the younger daughter of Enguerrand VII, Lord of Coucy, and Isabella of England. She was betrothed to Robert de Vere at the age of four and married him on 5 October 1376. Philippa was made a Lady of the Garter in 1378.

After her husband repudiated her and was granted a divorce in 1387, Philippa's situation caused a scandal, especially among her royal uncles. Despite the divorce, she continued to be styled as the Countess of Oxford and Duchess of Ireland. De Vere was exiled in 1388 and killed in 1392. The Pope declared the divorce invalid in 1389. Philippa later became an attendant of Richard II's second wife, Isabella of Valois, and accompanied her back to France after Richard's death in 1400. Philippa died in England on 24 September 1411, at around 44 years of age.