When did the Duchy of Aquitaine exist?

The Duchy of Aquitaine existed 10th century–1453. On this map it is drawn AD 990–1138, 1206–1362, 1375–1439.

How large was the Duchy of Aquitaine?

At its greatest extent drawn on this map, the Duchy of Aquitaine covered about 142,000 km². That is the largest area the border data gives it across the years it is drawn, not necessarily its greatest extent in history.

Europe · The early medieval west

Duchy of Aquitaine

10th century–1453

Duché d'Aquitaine; Occitan Aquitània; later Guyenne. Capital: Poitiers, later Bordeaux. Languages: Old Occitan, Poitevin, Gascon, Basque.

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Existed: 10th century–1453
Shown on the map: AD 990–1138, 1206–1362, 1375–1439 (3 periods)
Peak area: 142k km²
Region: Europe

Names

Duché d'Aquitaine; Occitan Aquitània; later Guyenne. Capital: Poitiers, later Bordeaux. Languages: Old Occitan, Poitevin, Gascon, Basque.

Development

A vast southwestern duchy ruled from the 10th century by the House of Poitiers (Ramnulfids), counts of Poitou. William VIII (1058–1086) united Gascony with Aquitaine. His son William IX "the Troubadour" (1086–1126), a leader of the Crusade of 1101, is celebrated as the earliest known troubadour, founder of Occitan vernacular lyric. William X (1126–1137) left as heiress his daughter Eleanor of Aquitaine (1137–1204).

The English connection

Eleanor married Louis VII of France in 1137 (bringing Aquitaine to the crown), but the marriage was annulled in 1152; she then married Henry Plantagenet, who became Henry II of England (1154), bringing Aquitaine into the Angevin Empire. For three centuries the duchy (as Guyenne/Gascony) was the great English possession in France, its Gascon wine trade with England hugely lucrative. It was the last English holding to fall, at Castillon (1453). Louis XI granted Guyenne to his brother Charles as an apanage (1469); it reverted to the crown in 1472.

Common questions

What was the Duchy of Aquitaine?: Duché d'Aquitaine; Occitan Aquitània; later Guyenne. Capital: Poitiers, later Bordeaux. Languages: Old Occitan, Poitevin, Gascon, Basque.
When did the Duchy of Aquitaine exist?: The Duchy of Aquitaine existed 10th century–1453. On this map it is drawn AD 990–1138, 1206–1362, 1375–1439.
How large was the Duchy of Aquitaine?: At its greatest extent drawn on this map, the Duchy of Aquitaine covered about 142,000 km². That is the largest area the border data gives it across the years it is drawn, not necessarily its greatest extent in history.

Sources

This compendium cites its sources once for the whole document rather than per territory. Its bibliography names the English Wikipedia articles for each territory as the primary basis, cross-checked against Encyclopædia Britannica and specialist snippets, and flags entries built on unreliable foundations — the 911 treaty of Saint-Clair-sur-Epte known only from Dudo of Saint-Quentin, and Arnaud Amalric's alleged order at Béziers attested only decades after the fact. The article this entry is anchored on:

Wikipedia — Duchy of Aquitaine en.wikipedia.org/wiki/Duchy_of_Aquitaine

This entry was last updated 27 September 2026.

This entry was researched and drafted with AI from the sources above, and has not been reviewed by a historian. How entries are made

Text available under CC BY-SA 4.0: reuse it with a credit to The World Through Time and a link to this page. Passages drawing on the Wikipedia articles listed above are also licensed CC BY-SA 4.0 by their contributors.

Border geometry for the map itself comes from Cliopatria v0.12 (Seshat Global History Databank, CC-BY-4.0).

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