Amphibalus
Saint "Amphibalus" is venerated as the early Christian priest who converted Saint Alban to Christianity. Alban sheltered the priest from religious persecution for a number of days, during which time Alban was so impressed with the priest's faith and teaching that Alban began to emulate him in worship, and became a Christian. When Roman soldiers came to seize the priest, Alban put on the priest's clothing and cloak, and went with the soldiers in the priest's stead. After Alban's martyrdom, Amphibalus escaped, but was eventually caught and also martyred.
Name
In the earliest accounts of the St. Alban story, such as the ones found in Gildas (c. 570) and Bede (c. 730), the priest is unnamed. It is not until the 12th century when he comes to be called "Amphibalus," and it is very unlikely that this was the genuine name of the priest. He is first called "Amphibalus" by Geoffrey of Monmouth, who may have misunderstood the Latin word used for the cloak, amphibalus, that was worn by Saint Alban. However, it is also possible that Geoffrey is simply repeating a name for the priest that had come into common usage by his time.