William I of Blois was Count of Boulogne

Count of Boulogne

The county of Boulogne was a historical region in the Low Countries. It consisted of a part of the present-day French département of the Pas-de-Calais , in parts of which there is still a Dutch-speaking minority....

 (1153–1159) and Earl of Surrey

Earl of Surrey

The Earl of Surrey is a title in the Peerage of England, and has been created five times. It was first created for William de Warenne, a close companion of William the Conqueror...

 jure uxoris (1153–1159). He was the third son of King Stephen of England

Stephen of England

Stephen , often referred to as Stephen of Blois , was a grandson of William the Conqueror. He was King of England from 1135 to his death, and also the Count of Boulogne by right of his wife. Stephen's reign was marked by the Anarchy, a civil war with his cousin and rival, the Empress Matilda...

 and Matilda of Boulogne

Matilda of Boulogne

Matilda I was suo jure Countess of Boulogne. She was also queen consort of England as the wife of King Stephen.-Biography:...

.

When his elder brother, Eustace IV of Boulogne

Eustace IV of Boulogne

Eustace IV was a Count of Boulogne and the son and heir of King Stephen of England. He became the Heir Apparent to his father's lands by the death of an elder brother before 1135, and inherited Boulogne through his mother, Matilda of Boulogne.In 1137, he did homage for Normandy to Louis VII of...

, died in 1153, William was passed over in the succession to England. His father instead conceded the throne to the young Henry Plantagenet

Henry II of England

Henry II ruled as King of England , Count of Anjou, Count of Maine, Duke of Normandy, Duke of Aquitaine, Duke of Gascony, Count of Nantes, Lord of Ireland and, at various times, controlled parts of Wales, Scotland and western France. Henry, the great-grandson of William the Conqueror, was the...

. The new King Henry was quite generous in his treatment of William of Blois, confirming his possession of the Earldom of Surrey jure uxoris (in right of his wife).

However, Gervase of Canterbury

Gervase of Canterbury

Gervase of Canterbury was an English chronicler.- Life :...

 asserts a plot against Henry's life was discovered in 1154 among some Flemish mercenaries. The plan was to assassinate Henry in Canterbury, and allegedly William of Blois had knowledge of this plot or was in connivance with the mercenaries. Whatever the truth, Henry fled Canterbury and returned to Normandy.

William of Blois had married Isabel de Warenne, 4th Countess of Surrey

Isabel de Warenne, 4th Countess of Surrey

Isabel de Warenne, Countess of Surrey was an English peeress. She was the only surviving heir of William de Warenne, 3rd Earl of Surrey and his wife, Adela, the daughter of William III of Ponthieu....

 in her own right, in 1148. They had no children before his death in 1159. He died before the gates of Toulouse, and was buried at the Poitevin abbey of Montmorel. He was succeeded as Count of Boulogne by his sister Marie

Marie of Boulogne

Marie I was the suo jure Countess of Boulogne from 1159 to 1170. She also held the post of Abbess of Romsey for five years until her abduction by Matthew of Alsace, who forced her to marry him.-Early years:Marie was the youngest daughter of King Stephen of England and his wife Matilda I, Countess...

. His widow remarried to Hamelin Plantagenet.

Annals of Monte Fernando 1159: "Ob. Willelmus comes Bolonie."

Arms: Gules, three palets vair, on a chief or, an eagle displayed gules membered azure.