Diarmaid the Just

Diarmaid the Just was an Irish monk and abbot of the 6th century, the founder of the monastery on the island of Inis Clothrann (Inchcleraun) in Lough Ree. He is a saint venerated in the West before the schism and was the spiritual father of Saint Ciaran of Clonmacnoise.

He was of princely descent, of the Hy-⁠Fiachrach family of Connacht, seventh in descent from King Nath Í; his mother was called Dediva. About the year 530 he founded the great monastery at Inchcleraun. Wishing for an oratory far from the distractions of the world, he chose the isolated island in the lake. His fame brought disciples, among them Ciaran of Clonmacnoise. He was a good teacher, writer and poet, composed psalters in verse and had Saint Senan as a friend. Tradition says that seven churches were built on the island; one, a tiny oratory of about eight feet by seven, is called Teampul Diarmada, the church of Diarmaid, and is said to have been his own. He also founded the monastery of Caille-⁠Fochladha near Lough Derravaragh, where a holy well bears his name.

The monastic school he founded kept its reputation for nearly six centuries, and the island remained a place of pilgrimage until the Reformation. He reposed around 542. His commemoration falls on 10 January.