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 one of my maternal 24 x great-grandfathers.

He was born as Guido in Chizé, Aquitaine, France, in 1023¹ son of William V and his third wife, Agnes of Burgundy¹.

Titles

In 1039, he became Count of Gascogne¹.

In 1044, he became Count of Bordeaux¹

In 1058, he took the name of Guillaume (William) when he succeeded his brother as¹:

• William VIII, Duke of Aquitaine.
• William VI Count of Poitiers.

Family

William married three times¹:

1. In January 1044 he married Aina of Perigord, divorcing her in November 1058 on the grounds of consanguinity.
2. His second wife, Mathilde bore him a daughter Agnes. He divorced her at some point after May 1068.
3. In March 1086, he married his third wife, Hildegarde of Burgundy in March 1069. She was his second-cousin, once-removed. 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 and Leon.

Hildegarde and William divorced 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

Various charters note his donation of property to religious orders¹:

• On 6 January 1049, he donated property to the monks of La Trinité, Vendôme. This is the same abbey his parents founded.
• In May 1068, he and his second wife donated the monastery of Saint-Porchaire de Potiers to the abbey of Bourgueil.
• He also donated land to the foundation of a new Abbey in Poitiers, the Abbey of Saint-Jean-De-Montierneuf.

The latter was no random donation; he built the abbey “as a form of penance” for marrying his second-cousin.

He must have been close to religious orders in various ways since in 1078, or 1079, he and his son determined entry conditions for monks at Saint-Hilaire de Poitiers by charter¹.

Military prowess

William ruled with an iron-fist and 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.

It 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.

Death

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

During the French Revolution, his body was exhumed and destroyed when church buildings were taken over by the state.

References

1. Cawley, Charles. (2024). AQUITAINE DUKES. [online] Available at: https://fmg.ac/Projects/MedLands/AQUITAINE.htm[↩][↩][↩][↩][↩][↩][↩][↩][↩][↩][↩][↩][↩]