Guillaume IV Talvas Count of Ponthieu
- Born: 1179, Ponthieu, Flandres, Belgium
- Marriage: Alys Countess of the Vexin on 20 Aug 1195 in Castile, Spain
- Died: 4 Oct 1221, France at age 42
Another name for Guillaume was William III.
William III Talvas (1179 - October 4, 1221) was William II (or III), Count of Ponthieu and William IV Talvas (of the house of Belleme/Montgomery). He was Count of Ponthieu, ruler of a small province in northern France that fell under the suzerainty of the dukes of Normandy (later also kings of England) since at least the mid 11th century. He was son and heir of John I, Count of Ponthieu (d 1191) by his third wife Beatrice de St Pol.
Family history and background
His father Jean I, Count of Ponthieu (d 1191 was the son and heir of Guy II, Count of Ponthieu (who died on the Second Crusade 1147), himself the son and heir of William III of Ponthieu. The great-grandfather William I, Count of Ponthieu (or William III Talvas) had surrendered the county of Ponthieu to his son Guy I for his lifetime, and then reobtained it after Guy's early death, which might explain why his great-grandson is usually known as William III Talvas.
William I Talvas, Count of Ponthieu was himself the son of Agnes, Countess of Ponthieu (d by 1105) by her husband, a notorious and powerful Norman baron Robert de Belleme, 3rd and last Earl of Shrewsbury, Lord of Montgomery; thus William III Talvas represented the senior line of the lords of Montgomery, once trusted vassals and allies of William the Conqueror.
Marriage to Alys, Countess of the Vexin
Talvas was married on August 20, 1195 to Alys, Countess of the Vexin, the daughter of King Louis VII of France. She was some eighteen years older than he, and had previously been the mistress of King Henry II of England while betrothed to his son, King Richard the Lion-Hearted. Richard sent her back to her brother, King Philip II of France, refusing to marry his father's mistress.
Philip then arranged for Alys to marry William Talvas, with the intent that the couple would be childless, and he would thus gain control of Ponthieu, a small but strategically important county. However, Alys then gave birth to a daughter and heiress, Marie, in 1197/1198. This daughter, the middle of three children, was the maternal grandmother of Eleanor of Castile, first wife of Edward I, King of England. Another genealogical table says that Alys and William III Talvas also had a son Jean (1199-1214 killed at Bouvines), while others attribute at least one more daughter to William and Alys.
In either case, at the death (in 1221) of William III Talvas, his daughter Marie was his heiress until her own death in 1251. For his marriage with Simon de Dammartin, count of Aumale, she bore 4 daughters, and Ponthieu then passed to her eldest daughter, Jeanne, wife of St Ferdinand, King of Castile and Leon. Jeanne died 1279, and Ponthieu and the disputed Vexin inheritance apparently formed the dowry/inheritance of Eleanor of Castile, wife of Edward I
Guillaume married Alys Countess of the Vexin, daughter of King Louis VII 'the Younger' Capet of France and Constanza Alfonsa Princess of Castile, on 20 Aug 1195 in Castile, Spain. (Alys Countess of the Vexin was born on 4 Oct 1160 in France and died in 1221.)