Alfonso, Count of Poitiers

Alphonse or Alfonso (11 November 1220 – 21 August 1271) was the Count of Poitou from 1225 and Count of Toulouse (as Alphonse II) from 1249.

Born at Poissy, Alphonse was a son of Louis VIII, King of France and Blanche of Castile. He was a younger brother of Louis IX of France and an older brother of Charles I of Sicily. In 1229, his mother, who was regent of France, forced the Treaty of Paris on Raymond VII of Toulouse after his rebellion. It stipulated that a brother of King Louis was to marry Joan of Toulouse, daughter of Raymond VII of Toulouse, and so in 1237 Alphonse married her. Since she was Raymond's only child, they became rulers of Toulouse at Raymond's death in 1249.

By the terms of his father's will he received an appanage of Poitou and Auvergne. To enforce this Louis IX won the battle of Taillebourg in the Saintonge War together with Alphonse against a revolt allied with king Henry III of England, who also participated in the battle.

Alphonse took part in two crusades with his brother, St Louis, in 1248 (the Seventh Crusade) and in 1270 (the Eighth Crusade). For the first of these, he raised a large sum and a substantial force, arriving in Damietta on 24 October 1249, after the town had already been captured. He sailed for home on 10 August 1250. His father-in-law had died while he was away, and he went directly to Toulouse to take possession. There was some resistance to his accession as count, which was suppressed with the help of his mother Blanche of Castile who was acting as regent in the absence of Louis IX. The county of Toulouse, since then, was joined to Alphonse's appanage.

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