The Church of the Magdalene was the ancient cathedral, but the Moors, objecting to its prominent position, compelled them to use a church on the outskirts of the town. In the records left by Miguel this was variously called Santa Maria de la Hidria, de la Vega, or de la Huerta, on account of its position. It was endowed by Teresa Cajal, mother of Pedro de Atarés and wife of García Sánchez, and was begun in 1152.
Bishop Moncada attempted to rebuild the beautiful cloister which had been destroyed in the War of the Two Peters, but as late as 1529 this had not been completed.
The episcopal palace, the ancient Azuda, is built upon a commanding eminence and has a beautiful view. Bishop Pedro Pérez Calvillo purchased this from the Aragonese governor, Jordán Pérez de Urries, in 1386, and entailed it to the bishopric.
The diocesan seminary, dedicated to St. Gaudiosus, was founded in 1593 by Bishop Pedro Cerbuna. It has recently been extensively renovated.
Turiaso was one of the principal towns of the ancient Celtiberian province, and within the confines of the diocese are found many very ancient cities: Bilbilis (Calatayud); Aquae Bilbilitanorum (Alhama); Atacum (Ateca); Augustobriga (Muro); Boverca (Buvierca); Bursao (Borja); Cascantum (Cascante); Gracuris (Corella); Monóbriga (Munébrega); and Vergegium (Verdejo). Pliny the Elder numbers Tarazona among the principal cities of the Celtiberians, and its inhabitants had the privileges of citizenship. Its coat of arms bore the motto "Tubal-Cain built me and Hercules rebuilt me".
Nothing definite is known of the origin of Christianity in Tarazona. Owing to its proximity to Saragossa it is supposed that it was visited at an early date by the disciples of Saint James the Great, but until the 5th century there is no reliable mention of a bishop of Tarazona.
The chronicler Idatius names Leo as bishop in 449; the chronological list of bishops gives St. Prudentius, but the history of this saint is uncertain. The Tarazona Breviary gives 390 as his date, but other sources place him as late as the 9th century. Idatius says that Leo was killed in an uprising led by a certain Basilius where the Bagandae took refuge in the cathedral, and in which a great number were killed.
St. Gaudiosus, a former monk of the Monastery of Asanense and a disciple of St. Victorian(us), was bishop in 530. He worked against the Arians, and died in his native city, Escoron. His remains were translated to the Monastery of Asanense, and King Sancho Ramirez had them removed to Montearagón.
When the Moors took Tarazona they were able to hold it for a long time on account of its fortified position near the Sierra del Moncayo, between the Douro and the Ebro rivers. The saints Attilanus and Iñigo of Calatayud were from this period.
King Alfonso Ithe Battler of Aragon took possession of Tarazona in 1119, and named Miguel Cornel as bishop. King Alfonso VII of Castile, in an effort to get possession of Tarazona, intruded a certain de Bujedo into the see; but de Bujedo repented shortly afterwards, restored the see to its rightful owner, Miguel, and retired to the Monastery of Valpuesta.
The Council of Burgos, which was convened in 1139, and was presided over by the legate Guido, took from the jurisdiction of Tarazona most of the towns of Soria, but bestowed in its place the Archdeaconry of Calatayud.
Miguel Cornel was the real restorer of the see. He governed for thirty-three years (1118–1151), and established the chapters of Tarazona, Calatayud, and Tudela, under the Rule of St. Augustine. In his time also were founded the Monasteries of Fitero and Veruela.
Three bishops of the name of Frontin succeeded him: Juan (1173–1194); Garcia, who was present at the battle of Las Navas de Tolosa (1212), and Garcia II, the counsellor of James the Conqueror (el Conquistador). In a species of national council held at Tarazona, the marriage of James to Leonor of Castile was declared null on account of the relationship existing between them. The Franciscans, Mercedarians, Dominicans, and Trinitarians, and the Cistercian and Poor Clare nuns were established in the diocese at this time.
Miguel Jiménez de Urrea, bishop from 1309 to 1316, was protected by king James II of Aragon, and during the time of Pedro Pérez Calvillo the war between Pedro IV the Ceremonious (el Ceremonioso) of Aragon and Pedro the Cruel of Castile took place. Tarazona was laid waste and its cathedral desecrated by the Castilians. The episcopal palace was burned, and la Zuda, sometimes also called Alcázar de Hércules, the palace of the Arab governors, was taken to replace it.
Bishops of Tarazona
ca. 449 : : Leo — (Mentioned in 449)
ca. 516 : : Paul — (Mentioned in 516)
527–541 : St. Gaudiosus
ca. 560 : : Didymus — (Mentioned in 560)
572–580 : St. Prudentius
589–592 : Stephen
ca. 610 : : Floridius — (Mentioned in 610)
ca. 635 : : Elpidius — (Mentioned between 633 and 638)
ca. 683 : : Antherius — (Mentioned in 683)
ca. 690 : : Nepotianus — (Mentioned between 688 and 693)