Clones was the site of a monastic settlement in the kingdom of Dartraige Con-innsi, originally founded by Tigernach (anglicised Tierney) in the 6th century, until the dissolution of the monasteries by Henry VIII. St. Tigernach or Tierney’s abbey, built in the early 6th century was dedicated to St. Peter and St. Paul. Tigernach later became Bishop of Clogher and removed that see to Clones, where he died of the plague in 550. The abbot was the Primus Abbas, or first mitred abbot of Ireland. The ruins of a 12th century abbey building can still be found in the town, along with a sarcophagus reputed to have been built to house the remains of Saint Tighearnach, and a 9th century round tower and high cross.