The Diocese of Dax or Acqs was a Roman Catholic ecclesiastical territory in Gascony in south-west France. According to tradition it was established in the 5th century.David M. Cheney, Catholic-Hierarchy.org Diocese of Acqs (Dax). Retrieved: 2016-08-01. It was suppressed after the French Revolution, by the Concordat of 1801 between First Consul Napoleon Bonaparte and Pope Pius VII. Its territory now belongs to the Diocese of Aire and Diocese of Bayonne.

History It is not certain that the patron of the diocese, the martyr St. Vincent, was a bishop. His cult, at least, existed in the time of Charlemagne, as is proved by a note (in a later hand) of the Wolfenbüttel manuscript of the Hieronymian Martyrology.He is called a bishop, but his See is not named. The oldest account of his martyrdom is in a breviary of Dax, dating from the second half of the thirteenth century, but the author knows nothing of the martyr's time period or the reasons for his death. Goyau takes his information directly from second edition (in French). Duchesne concludes that the martyr Vincent might have belonged to the time of the Roman persecutions, or to the fourth, or to the fifth century.

Excavations near Dax proved the existence of a Merovingian cemetery on the site of a church which, it is claimed, was dedicated to St. Vincent by Bishop Gratianus.The Merovingians were pagans, however, until after the conversion of Clovis, and they did not arrive in the area of Gascony until 531. Gratianus, present at the Council of Agde (506), is the first historically known bishop. Among the other bishops of the see were St. Revellatus (early sixth century), St. Macarius (c. 1060), Cardinal Pierre ItierPierre Itier had previously been Bishop of Sarlat: , citing a document in the Archives de la Dordogne which states, Dominus P(etrus) divina misericordia nunc Albanensis episcopus S.R.E. Cardinalis, tunc episcopus Sarlatensis... (1361), Cardinal Pierre de Foix (1455), founder of the University of Avignon and the Collège de Foix at Toulouse.

The synodal constitutions of the ancient Diocese of Dax, published by Abbé Antoine Degert, are of great historical interest for the study of the ancient constitutions and customs of the thirteenth and fourteenth centuries. Degert in the course of this publication succeeded in rectifying certain errors in the episcopal lists of the Gallia christiana and of Father Eubel in Hierarchia catholica.

During the Great Schism, Dax, which was part of Aquitaine, belonged to the Kings of England (in 1378 Richard II). King Richard chose to support the popes of the Roman Obedience rather than the popes of the Avignon Obedience, who were French and likely to support the King of France in what is now called the Hundred Years' War.Richard G. Davies, "Richard II and the Church," in: , pp. 94–96. All of the cardinals of the Avignon obedience were deprived of their offices and benefices in the Kingdom of Richard II of England, by act of Parliament and decree of the KingThomas Rymer, Foedera, Conventiones, Literae et cujuscunque generis Acta Publica inter Reges Angliae et alios quosvis... (Londini: A. & J. Churchill, 1708) VII, 222, 231-232, 271-273, and 294. Dax was required to adhere to the Obedience of Rome.

About 1588 St. Vincent de Paul made his first studies with the Cordeliers of Dax, but good secondary education at Dax dates only from the establishment of the Barnabites in 1640. His learning, however, was sufficient to allow him to study at the University of Toulouse.

On 3 June 1857, the title "Bishop of Dax" was added to the titulature of the Bishop of Aire.David M. Cheney, Catholic-Hierarchy: Diocese of Aire et Dax, retrieved: 2016-08-03.

Bishops of Dax Early bishops Vincentius Gratianus Carterius (541)Degert, pp. 35–37. Carterius was present at the IV Council of Orléans in 541. Liberius (549)Degert, pp. 37–39. Liberius was present at the V Council of Orléans. FaustianusDuchesne, p. 97, no. 4. Faustianus is mentioned only by Gregory of Tours (died 594), Historia Francorum, VII. 31, VIII. 2, and VIII. 20. Nicetius Illidius RevelatusDegert, p. 42. Revelatus is known only from the Breviary of Dax. A breviary is a prayer book, containing special prayers for Masses for local saints. It contains inspiring stories of these saints, proving they are worthy of the cult, and inspiring imitation of their virtues. It is a devotional book. It is hagiography. It is not history. Sede Vacante (lasting nearly four centuries, due to Arab invasions and Northmen, until ca. 850)Degert, pp. 43–47. Oltherius (second half of ninth century)Degert, pp. 47–48, based on what he admits is dubious evidence. Duchesne, p. 97, no. 6, states that Oltherius is mentioned in a charter of the Abbey of Sainte-Marie de Cagnote of the year 895, which he knows from Gallia christiana, based on some papers of [Dom Claude] d'Etiennot [de la Serre]. In other words, Duchesne has never seen any evidence. Cf. J. Depoin, "Un historien du Vexin: Dom Claude Estiennot", Mémoires de la Socété historique Pontoise, 28 (1907), pp. 183–190.

Bishops of Gascony Gombaud (end of tenth century)Degert, pp. 48–54. Arsius-RacaDegert, pp. 54–57. Some evidence, at least, concerning him is forged. Raymond RaymondDegert, pp. 65–68. Raymond 'the Younger' was the nephew of Raymond 'the Elder', his predecessor.

Bishops of Dax, 1000–1200

MacariusDegert, pp. 66–69. Macarius was Bishop of Dax for less than three years, one of which was 1061). (ca. 1061) Gregory de Montaner, O.S.B.Degert, pp. 69–73. Gregory had been raised at Cluny, by Saint Hugh. He was appointed Abbot of Saint-Severus in the diocese of Aire, thanks to the patronage of Sancho Guillaume, Duke of Gascony; then he became Abbot of Soule. He died on 11 January 1072). ( –1068) Bernard de Mugron, O.S.B.Degert, pp. 74–80. He had been a monk of Saint-Severus in the diocese of Aire (Adurensis): Gallia christiana I, pp. 1173–1175. (by 1068 – 25 July 1097) Raymond de SentesDegert, pp. 81–90. The successor was not Archdeacon Raymond-Arnaud, as in Gallia christiana I, p. 1044; Arnaud-Raymond died of violence before the death of Bernard de Mugron. (before 1100 – 28 March 1117) Guillaume de HeugasDegert, pp. 91–98. (1117–1143) Arnaud-Guillaume de SortDegert, pp. 98–104. (ca. 1143 – after 20 November 1167) Guillaume BertrandDegert, pp. 104–109. Guillaume Bertrand was the third son of the Vicomte de Bayonne. (ca. 1168–1203)

1200–1400

? Jean de CaunarDegert, pp. 109–111. (1203) Fortanerius de Mauléon (1204 – February 1215) Guilelmus de Salies (1217 – October 1233) Arnaud Raymond de TartasDegert, pp. 128–130. (1234–?) Navarre de Miossenx, O.Cist.Degert, pp. 130–138. (1239 – 3 November 1272) Sede Vacante (1272–1278)There was a prolonged struggle in the Chapter of the Cathedral of Dax, of which there were nine members, between the supporters of Arnaud de Ville (5 votes) and Pierre de Camone, O.Min. (3 votes). One voted for Raymond de Barde of Auch. De Ville had a majority, but not a canonical majority or a consensus. The matter was appealed to Rome, where Gregory X assigned the matter to Cardinal Giacomo Savelli for investigation. Pierre de Camone came to die, and his followers then turned to Garsias Arnaud de Capenne. Arnaud de Ville was cited to appear personally before John XXII, but the Pope died before he could make the journey. Nicholas III appointed three cardinals to examine Arnaud, and, upon their favorable report, he was appointed Bishop. Digert, pp. 139–140. Arnaud de VilleDegert, pp. 138–148. (5 April 1278 – 11 March 1305) Garsias Arnaud de CapenneDegert, pp. 148–160. Bishop Garsias was elected by the Chapter of the Cathedral, and confirmed by Pope Clement V. (1305, before 12 September – 8 January 1327) Bernard de LiposseDegert, pp. 161–170. (19 January 1327 – February 1359)Gallia christiana I, p. 1051, and Gams, p. 543, attempt to insert a Bishop Matthew and a Bishop Bertrand after Bishop de Liposse. 'Bishop' Matthew was only Abbot of Charoux, and his 'Constitutions' are mythical: Degert, p. 171. Bishop Bertrand is really Bishop Bernard de Liposse. Pierre la Colre (15 March–15 April 1359)Eubel, I, p. 97. Degert, pp. 171–172. Pierre la Colre had been Vicar General of the Diocese of Bordeaux, as well as Canon and Sacristan of the Cathedral of Dax. He was buried in the church of Lunello in the diocese of Nîmes, which is probably the place of his death. Pierre Itier (10 May 1359 – 1362)Degert, pp. 173–174. Pierre Itier had previously been Bishop of Sarlat. He was created Cardinal Priest on 17 September 1361, and assigned the titulus of Santi Quattro Coronati in Rome. (resigned on becoming Cardinal) Bernard d'Albret [de Lebreto], O.Min. (Bishop-elect)Degert, pp. 174–176. Bishop Bernard d'Albret was the fourth son of Bernard Ezi II d'Albret and Mathe d'Armagnac. He died in the same year, 1362, and was never consecrated. (1 June–?, 1362) Jean de SayaDegert, pp. 176–183. (18 January 1363 – 8 June 1375) (transferred to Agen)Eubel, I, p. 77. Jean de Saya had already been Bishop of Lombès (1362–1363) before his transfer to Dax. Jean de Hanecourt [or Haricuria] (bishop-elect, died before consecration) (9 June–August 1375)Degert, pp. 183–184. Eubel, I, p. 97. Jean BauffèsDegert, pp. 184–188. (27 August 1375 – 4 December 1391) (transferred to Vich)Eubel, I, p. 526. Jean Bauffès remained loyal to the popes of Avignon, Gregory XI and Clement VII. Joannes Guterii (Obedience of Rome)Degert, pp. 188–199. (March 1380 – late in 1393) Pierre Troselli, O.P. (Obedience of Avignon)Degert, pp. 199–202. Doctor of Theology. Troselli was suspended on 9 March 1405 by Benedict XIII (Pedro de Luna) of the Avignon Obedience, and Nicolas Duriche, O.P., was appointed Vicar-General. (4 December 1391 – 9 March 1405? or 1412?) Pierre du Bosc (Obedience of Rome)Appointed by Boniface IX (1389–1404). Eubel, I, p. 97. Degert, pp. 202–206. (5 December 1393 – 19 June 1400)

1400–1600

Petrus Ameil de Brénac, O.E.S.A., Patriarch of Alexandria (Obedience of Rome), Administrator of DaxDegert, pp. 206–207. (19 June 1400 – 4 May 1401) Garsias-Arnaud de Navailhes (Obedience of Rome)Degert, pp. 207–210. He resided in the diocese, and held a synod on 18 September 1401. (4 May 1401 – 1407) Pélegrin du Fau (1407 – 22 July 1408)Degert, pp. 210–212. Du Fau, from Orthez in the diocese of Dax, Canon of Saint-André de Bordeaux, was appointed by Gregory XII (Obedience of Rome). Petrus de Anglada, O.P. (Obedience of Rome) (23 August 1409 – 1423) Nicolaus Duriche, O.P. (Obedience of Avignon) (27 May 1412 – 1423)Degert, pp. 216–219. Francesco Piccolpasso (29 March 1423 – 26 February 1427)Eubel, I, p. 97. Degert, pp. 219–222. (transferred to Pavia)Piccolopasso was appointed to the diocese of Pavia on 26 February 1427 by Pope Martin V: Eubel, I, p. 390. Bernard de la Planche (26 February 1427 – 1439) (deposed, as a supporter of Antipope Felix V)Eubel, II, p. 91, note 1. Degert, pp. 222–227. Garsias Arnaldi de Sega (de l'Exègne)He had been Provost of the Collegiate Church of S. Severinus near Bordeaux. (25 September 1439 – 9 December 1444)Garsias Arnaldi was transferred to the diocese of Bayonne on 9 December 1444: Eubel, II, p. 101. Beltrandus (1445? – 5 July 1451)Eubel, II, p. 206. He died in the same year. (transferred to the diocese of Oloron) Pierre de Foix, O.Min. (5 July 1451 – 30 May 1459) Jean de Foix (1459 – 9 May 1466) (transferred to Comminges)Eubel, II, p. 135. Bertrand de Borie (12 May 1466 – 1499)Bishop de Borie assisted at the coronation of Jean III d'Albret and Queen Catherine as rulers of Navarre at Pamplona on 10 January 1094. He resigned in favor of his nephew in 1499. Arnaldus (Garsias Arnaud) de Borie (8 April 1499 – 1501) Petrus de Caupena (6 February 1502 – 1514) Jean de la Martonie (1514–1519) Gaston de la Martonie (1 April 1519 – October 1555)Dufourcet, p. 225.