Life and Foundation at Connor
The synaxarion and Irish hagiographers relate that Mac Nisse was baptized by Saint Patrick, in one account in a fountain of water said to have sprung miraculously from the earth, and that Patrick instructed him in the psalms and later raised him to the episcopate. He was fostered with Olcan, bishop of Armoy, another of Patrick's disciples.
He is thought to have lived earlier as a hermit, by some accounts near Kells, before he chose the district of Connor for his settlement. There he founded a religious community and became bishop of his people, governing the foundation until his repose. Because the sources are late and devotional, the chronology is uncertain; the dating of his death varies in the annals around the year 514.