 Lanigan and Leslie Stephen place him in the 5th century, based on anecdotes that make him a contemporary of Ciarán of Clonmacnoise, Brendan of Birr, and Brendan of Clonfert.Lanigan suggests that Ciarán of Saighir was one of Finnian of Clonard's first students, and indicates that he was likely bishop sometime prior to 544.Legends attribute remarkable miracles to Ciarán.