Clan Dermod Descended from Dermod Donn, a son of Donal Gott MacCarthy, Lord of Carbery (1205-1251) and was founded in the late 13th century. The clan possessed an extensive district in Carbery and the castles of Kilcoe and Cloghan. Little has been researched or written on the Clan Dermod and therefore an attempt has been made to relate the history of the castle with that of the clan.
The name Kilcoe comes from Cill Coiche (Church of St. Coch. a nun supposed to have been a companion of St. Kieran) and is referred to as Cellcohi in the Decreatal Letter of 1199. The remains of the church are near to the castle.
Kilcoe Castle was built in the 15th century at the height of Clan Dermod’s prosperity and was the residence of the chief. It is located on the small rocky island of Mannin Beg overlooking Roaring Water Bay.
Although it was always called Kilcoe Castle it is strictly speaking a Tower House. These were not castles in the pure military sense but functioned as fortified private residences of the local chiefs and families. Both terms are used in the text. The article in the Mizen Journal 1999 on Dunmanus Castle considered various aspects of the use and details of Tower Houses.
The text above is from the article “Kilcoe Castle and Clan Dermod MacCarthy” by John Hawkes published in the Mizen Journal.