Gaston I of Foix or Gaston VIII of Foix-Béarn (1287 - Maubuisson, December 13 1315) was the 9th Count of Foix and the 22nd Viscount of Béarn.

He was a son of Roger-Bernard III, Count of Foix and Margaret of Montcada, the eldest daughter and heiress of Gaston VII of Béarn. He succeeded his father in 1302 as Count Gaston I of Foix and Viscount Gaston VIII of Béarn, first under the regency of his mother.

He was probably present at the Battle of the Golden Spurs in 1302, and fought again for the King of France against the Flemish at the Battle of Mons-en-Pévèle in 1304.
When the cities of his County of Foix rebelled against the Royal tax collectors, because they raised the taxes to finance the expensive war against Flanders, Gaston supported his cities. For this, the County was confiscated for a while by the Senechal of Carcassonne.

In 1308 he started a war against the Count of Armagnac, against the orders of the King, who had forbidden intra-French warfare. Gaston is taken prisoner and locked up in the Châtelet. He is only released after paying a ransom of 36,000 pond.

In 1310 he inherites the Viscounty of Marsan from his aunt Constance of Moncada.

Marriage and children

Gaston married in 1301 Joan of Artois (1289-1350), daughter of Philip of Artois and Blanche of Brittany.
They had 6 children:

• Gaston II de Foix, Count of Foix, Viscount of Béarn (1308 – 26 September 1343).
• Roger Bernard IV de Foix (1310 – after 24 March 1350), married Constanza de Luna (1310 – January 1353), daughter of Artal de Luna, by whom he had three children.
• Robert de Foix, Bishop of Lavaur
• Margaret of Foix
• Blanche de Foix, married in 1328 Jean de Grailly, Viscount of Castillon, Captal de Buch, by whom she had two children, including Jean de Grailly, Captal de Buch.
• Joan of Foix (died 1358), married Infante Peter of Aragon, Count of Ribagorza y Ampurias, by whom she had three children, including Eleanor of Aragon, Queen of Cyprus.