Richard De Cogan
From A Compendium of Irish Biography, 1878
De Cogan, Richard, younger brother of preceding, specially distinguished himself in the defence, above mentioned, of Dublin. He is spoken of as having been appointed to the command of a picked body of troops by King Henry II. and sent into Ireland to supply the place of his brother Milo.
148. Giraldus Cambrensis: Topography, and History of the Conquest in Ireland: Forester and Wright. London, 1863.