In 304, during the persecution of Diocletian, the Bishop of Cesaraugusta (Zaragoza) Valero and his deacon Vincent, were led to Valentia. Vincent suffered such an admirable martyrdom in this city that it was known and celebrated throughout the whole Christendom.

The hymns of Aurelius Prudentius, the homilies of Saint Augustine and the stories of the passion of Saint Vincent made him the most popular martyr of the Latin Church, to the point that many towns were founded with his name and monasteries and cathedrals were erected such as those of Córdoba, Seville and Bergamo.

During the Roman and Visigothic period, in the Valencian region the local churches of Diana (Denia), Ilice (Elche), Saetabis (Xátiva), Elo (Lorca or Hellín) and Valentia (Valencia), flourished, and we know the names of many of its Bishops for their signatures in the councils of the 4th – 8th centuries.

This Christian culture and life remained long-suffering and silenced under Islam, having martyrs such as Saint Bernard and his sisters Mary and Grace (1189) or the blessed Franciscans John of Perugia and Peter of Sassoferrato (1228). The Christian worship was not interrupted in the Saint Vincent’s crypt basilica (La Roqueta), outside the city walls, resulting as spiritual fruit this Mozarabic Church to Saint Peter Pascual, then Bishop of Jaén and martyr in Granada in 1300.

A new period opened with the founding of the Kingdom of Valencia by James I of Aragon in 1238, being the first Bishop Ferrer de Pallarés.

Subsequently, settlers from the northern regions of the Crown of Aragon, monastic, military and religious orders arrived, and a new organization of the dioceses was established, leaving the north of the Kingdom in Tortosa, reinstating those of Segorbe and Valencia, and creating later the diocese of Orihuela, in the 16th century (1564).