[2] Coonagh Castle is located 2.6 km (1.6 mi) west-southwest of the village of Doon, County Limerick.

[4] It was the capital manor of the medieval cantred of Okonagh or Oconagh, equivalent to the ancient barony of Coonagh.

There may have been an earlier fort on the site, built by William de Braose, 4th Lord of Bramber in the 12th century.

It was later passed to Matilda, a relative of King Henry II, when she married William de Marisco some time before 1226.

[3] In November 1234 the de Mariscos lost the castle as punishment for siding with Richard Marshal, 3rd Earl of Pembroke against the King.