Native name |
Irish: Carraig Mhic Dhiarmada
Castle Island, Lough Key,|
County Roscommon, Ireland
|Official name: McDermott's Castle (Castle Island)|
The Mac Diarmada were the ruling dynasty of Magh Luirg (Moylurg; northeast Connacht) from the 10th to 16th centuries. A castle stood on this island from the 12th century: in 1184, the Annals of Loch Cé report that a lightning bolt caused a fire:
The Rock of Loch-Cé was burned by lightning, i.e. the
very magnificent, kingly residence of the descendents of Máel Ruanaid
where neither goods nor people of all that were
there found protection; where six score, or seven score, of
distinguished persons were destroyed, along with fifteen
men of the race of kings and chieftains, with the wife of
Mac Diarmada, i.e. the daughter of Ó hEidhin, and his
son's wife, i.e. the daughter of Domhnall O'Conchobhair,
and the daughter of Ó Dubhda, and the son of Donnchadh
O'Maelbhrenuinn, and the son of Donn O'Mannachain,
and the two daughters of O'Mannachain, and Mac Maenaigh,
chieftain of Cenél-Builg, and the priest O'Maelbealtaine,
and Gillachiarain Ó Connachtain, (i.e. a son of
chastity and lamp of piety), and a countless destruction
besides of good men; and every one of them who was not
burned was drowned in this tumultuous consternation,
in the entrance of the place; so that there escaped not
alive therefrom but Conchobar mac Diarmata with a
very small number of the multitude of his people.
A rebuilt castle featured in the final part of the 1235 conquest of Connacht by Richard Mór de Burgh, 1st Baron of Connaught. The castle came under siege, first by a raft-mounted catapult, and then by fire ships. Cormac MacDermott, King of Moylurg, was forced to surrender.
A poem addressed to Tomaltach an Einigh mac Diarmata (King of Moylurg 1421–58) tells the story of the Hag of Lough Key who used (or abused) Cormac MacDermott's (king 1218–44) hospitality by staying on the Rock for a full year, and laid upon the McDermotts the obligation of perpetual hospitality.
In 2014 the island and castle featured in an episode of sitcom Moone Boy, as the residence of the mysterious "Island Joe."
Isaac Weld, writing in 1832, describes as part of "the castle proper" two rooms, one above the other, each 36 × 22 feet (11 × 7 m), with walls 7½ feet (2.2 m) thick. It is not clear whether this refers to part of the original castle, or the later construction.