William III of Ponthieu was son of Robert II of Bellême and Agnes of Ponthieu

Agnes of Ponthieu

Agnes of Ponthieu was the daughter of Count Guy I of Ponthieu. Enguerrand, the son of Count Guy, died at a youthful age. Guy then made his brother Hugh heir presumptive, but he also died before Guy . Agnes became count Guy's heiress, and was married to Robert of Bellême...

. He is also called William (II; III) Talvas.

He assumed the county of Ponthieu

Count of Ponthieu

The County of Ponthieu , centered on the mouth of the Somme, became a member of the Norman group of vassal states when Count Guy submitted to William of Normandy after the battle of Mortemer.....

 some time before 1111, upon the death of his mother. His father escaped capture at the battle of Tinchebrai (1106). Later, as envoy for King Louis

Louis VI of France

Louis VI , called the Fat , was King of France from 1108 until his death . Chronicles called him "roi de Saint-Denis".-Reign:...

 of France

France

The French Republic , The French Republic , The French Republic , (commonly known as France , is a unitary semi-presidential republic in Western Europe with several overseas territories and islands located on other continents and in the Indian, Pacific, and Atlantic oceans. Metropolitan France...

, he went to the English court. He was arrested by King Henry

Henry I of England

Henry I was the fourth son of William I of England. He succeeded his elder brother William II as King of England in 1100 and defeated his eldest brother, Robert Curthose, to become Duke of Normandy in 1106...

 of England

England

England is a country that is part of the United Kingdom. It shares land borders with Scotland to the north and Wales to the west; the Irish Sea is to the north west, the Celtic Sea to the south west, with the North Sea to the east and the English Channel to the south separating it from continental...

 and was never released from prison. William was naturally driven by this to oppose King Henry and his allegiance to count Geoffrey of Anjou caused Henry to seize certain of William's castles in Normandy.

Family

His wife was Helie of Burgundy

Helie of Burgundy

Helie of Burgundy was the daughter of Eudes I and Sibylla of Burgundy.In June 1095, she married Bertrand of Toulouse, as his second wife. The two had one son, Pons of Tripoli ....

, daughter of Eudes I, Duke of Burgundy

Eudes I, Duke of Burgundy

Odo I , also known as Eudes, surnamed Borel and called the Red, was Duke of Burgundy between 1079 and 1103. Odo was the second son of Henry of Burgundy and grandson of Robert I. He became the duke following the abdication of his older brother, Hugh I, who retired to become a Benedictine monk...

. The Gesta Normannorum Ducum

Gesta Normannorum Ducum

Gesta Normannorum Ducum is a chronicle originally created by the monk William of Jumièges just before 1060. In 1070 William I had William of Jumièges extend the work to detail his rights to the throne of England. In later times, Orderic Vitalis and Robert of Torigni Gesta Normannorum Ducum (Deeds...

says that they had five children, three sons and two daughters. Guy II

Guy II of Ponthieu

Guy II of Ponthieu , the son of William III of Ponthieu and Helie of Burgundy, succeeded his father as Count of Ponthieu during William's lifetime. He died on the Second Crusade and was succeeded by his son John I of Ponthieu....

 is called "the eldest son", but the editors doubt this. He assumed the county of Ponthieu during his father Talvas' lifetime, but preceded him in death (Guy II died 1147; William Talvas died 1171). His daughter married Juhel, son of Walter of Mayenne, and his daughter Adela (aka Ela) married William de Warenne, 3rd Earl of Surrey

William de Warenne, 3rd Earl of Surrey

William de Warenne, 3rd Earl of Surrey was the eldest son of the William de Warenne, 2nd Earl of Surrey and Elizabeth de Vermandois.He was generally loyal to king Stephen...

.

Source

• The Gesta Normannorum Ducum of William of Jumièges, Orderic Vitalis, and Robert of Torigni, edited and translated by Elisabeth M. C. Van Houts, Clarendon Press, Oxford, 1995.