William VIII, Duke of Aquitaine

William VIII was key to one of the first military campaigns the Pope organised against the Muslims in Spain. This was a precursor to the Crusades.

He is my 24 x great-grandfather.

He was born in Aquitaine, France, between 1023¹ and 1025, as Guy d’Aquitaine¹, son of William V and his third wife, Agnes of Burgundy¹.

Titles

In 1058, he took the name of Guillaume (William) when he succeeded his brother as William VIII, Duke of Aquitaine, and William VI Count of Poitiers¹.

The coat of arms of the House of Poitiers
By Ipankonin – Modified; CC BY-SA 3.0

Family

William married three times¹:

In 1044 he married Aina of Perigord, divorcing her in November 1058 on the grounds of consanguinity.
His second wife, Mathilde bore him a daughter Agnes. He divorced her in 1068.
He married his third wife, Hildegarde of Burgundy in March 1069. She was his cousin. Together they had four children:
1. Godfrey, who succeeded his father as William IX, Duke of Aquitaine.
2. Hugh.
3. Agnes, who married Pedro I, King of Aragon.
4. Beatrix, who married Alfonso VI, King of Castile y Leon.

Hildegarde and William separated in 1076¹.

It’s possible William also had 3 illegitimate children¹:

Agnes
Two unnamed children who are only recorded because of their own children.

Notable events

William extended the territory he ruled over, pushing as far south as Toulouse¹.

In 1064 he led an army to invade Muslim-controlled Spain.

This was the siege of Barbastro.

This was a controversial invasion but also provided the Roman Catholic church with a template for the Crusades. William’ continuing interest in Spanish politics is clear; he did marry all his daughters off to Spanish nobility.

In 1078, or 1079, he and his son determined entry conditions for monks at Saint-Hilaire de Poitiers by charter¹.

Death

He died in Aquitaine, France on 25 September 1086 of unknown causes¹. They buried him in Poitiers in the Abbey church of Saint-Jean l’Evangéliste de Montierneuf¹.

Lineage