The strategic location of the monastery helped it become a major centre of religion, learning, craftsmanship and trade by the 9th century and together with Clonard it was the most famous in Ireland, being visited by scholars from all over Europe. Until the 9th century it had close associations with the kings of Connacht and then until the 11th century it was alliance with the kings of Mide. Many of the high kings of Tara and Connacht were buried here. It was attacked frequently, by the Vikings, Anglo-Normans and other Irish forces.
All the early buildings including churches were of wood and have not survived. They were replaced in stone by the tenth century onwards when Clonmacnoise became a bishopric. It also produced many fine examples of Celtic gold and silverware, which is preserved in Dublin museums.
After the 12th century it fell into decline. The English built a castle next to the monastery in the 13th century, it was sacked in 1552 by the English who reduced it to ruin.