St Comgall was a pupil of St Finnian of Clonard and also St Ciaran of Clonmacnoise. He founded a strict monastery on an island of Lough Erne and founded another at Bangor on the southern shore of Belfast Lough. His Rule still exists.
St Comgall was a close friend of St Columba and St Cannice. The three worked closely together in the Inner Hebrides.
He founded a monastery on the island of Tiree.