Alys of France, Countess of Vexin

[close] Alys of France, Countess of Vexin (4 October 1160 – c. 1220) was the daughter of King Louis VII of France and his second wife, Constance of Castile. Alys was the half-sister of Marie and Alix of France, Louis's children by Eleanor of Aquitaine, and the younger sister of Margaret of France. Just five weeks after Constance died giving birth to Alys, Louis married Adèle of Champagne, by whom he had two further children, including the future Philip II of France.

In January 1169, Louis and Henry II of England signed a contract for the marriage between Alys and Henry's son Richard. The 8-year-old Alys was then sent to England as Henry's ward.

In 1177, Cardinal Peter of Saint Chrysogonus, on behalf of Pope Alexander III, threatened to place England's continental possessions under an interdict if Henry did not proceed with the marriage. There were widespread rumors that Henry had made Alys his mistress,. Henry died in 1189. King Richard married Berengaria of Navarre on 12 May 1191, while still officially engaged to Alys.

Philip had offered Alys to Prince John, but Eleanor prevented the match. Alys married William IV Talvas, Count of Ponthieu, on 20 August 1195. They had two daughters: Marie, Countess of Ponthieu, and Isabelle; and a stillborn son named Jean.