Ceanannus Mór, market town and urban district of County Meath, Ireland, on the River Blackwater. The town was originally a royal residence. In the 6th century it was granted to St. Columba and became a centre of learning. A bishopric was founded there about 807 and was united to that of Meath in the 13th century. The house of St. Columba, later converted into a church, was built about 807. Near the present church is a round tower, and there are several ancient crosses still standing in the locality. The Book of Kells, an illuminated copy of the Gospels in Latin that contains local records, was probably completed there in the early 9th century. Preserved in the library of Trinity College, Dublin, it is one of the finest extant examples of Hiberno-Saxon manuscript art. The town’s industries include the manufacture of computer cabinets. Pop. (2006) 2,257; (2011) 2,208.