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.
Given its closeness to Saragossa, it is likely that Tarazona was visited by followers of Saint James at an early time. However, there is no documented evidence of a Tarazona bishop until the 5th century.