The diocese of Oleron already existed in the 6th century, when Bishop Gratus attended the Council of Agde. The diocese of Oleron was a suffragan provincial subordinate to the Archdiocese of Eauze , holding the eighth place of nine, until Eauze was destroyed by the Normans around For administrative purposes the diocese was subdivided by the thirteenth century into six archdeaconries, those of Oleron, Soule, Navarrenx, Garenz, Aspe, and Lasseube.
The Bishop and Chapter were jointly seigneurs of the town of Sainte-Marie, on the opposite bank of the river Gave from Oloron, where the episcopal palace was located. It had a Chapter composed of a Sacristan and twelve non-residential Canons. Bishop Amatus ? On 6 October , Amat and Hugh presided at another council at Bordeaux; and likewise in the same year at Saintes, and likewise on 27 March at Issoudun Exoldunense.
The reward for this very busy and loyal bishop was a promotion to the Archbishopric of Bordeaux Late in May or early in June , the Canons of the Chapter of the Cathedral of Saint-Marie assembled, and in accordance with canon law conducted an election by scrutiny for a new bishop. They immediately notified Pope Innocent IV , who was staying at Lyon at that time, and drew his attention to the Elect's sterling qualities, but also to the fact that the bishop-elect was not eligible for the office super natalium defectu illegitimacy.
The Chapter requested that the Pope dispense Pierre from this obstacle to his promotion. The Pope appointed a committee of three bishops, the Archbishop of Auch and the bishops of Lascar and Dax Aquensis , to inquire into the canonical form of the election, the behavior of the petitioners, and the merits of the Elect.
They were to inform the Pope immediately of their findings, which they did, and which were all positive. On 14 July Pope Innocent provided the necessary dispensation and the mandate to the Archbishop to consecrate Pierre de Gavarret as Bishop of Oloron.
