Jourdain de L'Isle, out of gratitude to his benefactor aunt, who had left him her estate, named the new town Vianne.
Vianne de Gontaut Biron, namesake of the Bastide de Vianne (1225–1280)
Vianne de Gontaut-Biron went down in the history of Albret thanks to the decision of her nephew, Jourdain de L'Isle, who founded a fortified town in 1284 named Vianne in honor of his aunt, who had left him her estate. Her life was also marked by a troubled marriage, during which two papal bulls annulled her marriages.
The eldest daughter of the Lord of Montgaillard, Vital de Gontaut-Biron, Vianne inherited the Château de Montgaillard and its outbuildings, including Villelongue, Puch, and Gontaud en Agenais, upon her father's death.
Vianne, who owned numerous properties, had no trouble finding a husband of her own rank. She married Amanieu VI, Lord of Albret and Lord of Nérac, who received Vianne's dowry consisting of all her possessions: lands, estates, and castles.
Despite their considerable wealth, Vianne and Amanieu had a difficult married life and wanted to separate. At that time, the sacred bond of marriage could only be broken by the Pope through a papal bull and for valid reasons.
They then found an impediment that could render their marriage null and void: they invented a false spiritual kinship, also known as spiritual consanguinity. This ecclesiastical law prohibited a godfather or godmother from marrying their godchild without a papal dispensation. However, Vianne argued to Pope Clement IV that her father-in-law was also her godfather and that she therefore could not be Amanieu's wife, which was false...
Vianne and Amanieu provided false evidence and testimony attesting to this spiritual kinship, and the Pope, deceived by their trickery, issued a bull on September 22, 1268, declaring their marriage null and void.
Vianne de Gontaut-Biron then married Hélie de Castillon, a lord from Bazas, in what is now Gironde, to whom she brought all her possessions recovered from her previous husband. This second marriage was no happier than the first, and Vianne wished to separate from Hélie and return to Amanieu VI!
Vianne then proved to Pope Gregory X that the evidence and testimony that had led to her separation from Amanieu VI were false, and a new papal bull issued in 1271 annulled her second marriage.
Vianne once again recovered her dowry, which she immediately bequeathed not to a new husband but to a member of her family, her nephew Jourdain de L'Isle. In 1271, this lord received the castle of Montgaillard and its outbuildings. In a spirit of repentance, Vianne, probably anxious to ensure her salvation, devoted herself to pious foundations. In 1261, she founded the Dominican convent in Condom and contributed to the founding of other convents for noble young women. Vianne de Gontaut-Biron died in 1280 in the residence she had built at the convent in Condom.
At the end of the13thcentury, Vianne, formerly known as Villeongue, was part of the seigneury of Montgaillard. This territory, which had been under English rule since the cession of Agenais by the French king Philip the Bold to England in the Treaty of Amiens in 1279, was threatened by the founding of a French bastide in 1260 just a few kilometers away: Lavardac. The Aquitanians, wishing to protect and fortify their territory against this French threat, decided to build a bastide.
To found this new town, Jourdain de L'Isle, lord of the jurisdiction of Montgaillard, had to reach an agreement with the representative of EdwardI, Duke of Aquitaine and King of England, a certain Jehan de Grailly, seneschal of Agenais. On November 22, 1284, the treaty establishing the future bastide was signed by deed of paréage. Jourdain de L'Isle and the seneschal of Agenais shared the rights of justice and the revenues generated by the bastide.
Jourdain de L'Isle, out of gratitude to his benefactor aunt, who had left him her estate, named the new town Vianne.
