It is a modest collection of remains for a place that was, at various points across more than a thousand years, a Viking target, a venue for high politics, a fortified Anglo-Norman settlement, and a chartered town. The gap between what once stood here and what survives is itself the story.

The monastery was founded in the sixth century by Saint Colum mac Cremthainn, with the annals recording his death in 552. The Vikings attacked it in the ninth century, and unknown assailants struck again in the twelfth. Despite this, the site retained enough prestige that in 1140 a peace treaty between the O'Brien and O'Connor dynasties was arranged here, suggesting it functioned as neutral or sacred ground in the fractious politics of the period. Anglo-Norman interest followed: by 1219, John Marshall, possibly a brother of William Marshall, Earl of Pembroke, had not yet fortified the place, though by 1290 a William Marshall held the lordship and may have built a castle on the nearby lakeshore. A 1335 inquisition records William de Burgo's lands as including a castle, a manor held of the see of Killaloe, and a mill in the town of Tyrdegals, and references from 1333 to burgages and burgage rent suggest the settlement had at some point received a town charter. Burgages were plots of land granted to tenants under a borough charter, the standard mechanism by which medieval lords encouraged urban settlement. The medieval church, which contributed three marks to a diocesan taxation between 1302 and 1307, had apparently fallen into such disrepair by the mid-seventeenth century that the Civil Survey of 1654 to 1656 mentions only the churchyard. Beside that churchyard, a bawn, the walled enclosure typically built to protect a tower house or manor, was constructed in the late sixteenth or early seventeenth century, probably to control the Shannon crossing against incursions from Connacht. A substantial earthwork running just north of the village may relate to the early monastery, or to these later military concerns; no one is entirely sure.