Palladius was the first bishop of the Christians of Ireland, preceding Saint Patrick. It is possible that some elements of their life stories were later conflated in Irish tradition. Palladius was a deacon and member of one of the prominent families in Gaul. Pope Celestine I consecrated him a bishop and sent him to Ireland "to the Scotti believing in Christ".

Secundinus, or Sechnall as he was known in Irish, was founder and patron saint of Domhnach Sechnaill, County Meath, who went down in medieval tradition as a disciple of St Patrick and one of the first bishops of Armagh. Historians have suggested, however, that the connection with St Patrick was a later tradition invented by Armagh historians in favour of their patron saint and that Secundinus is more likely to have been a separate missionary, possibly a companion of Palladius.