General Notes

Miles (Milo) de Cogan, a younger son of the Cogans of Glamorgan, took a leading part in the 12th century Anglo/Cambro-Norman incursion into Ireland and was granted by Henry II 1177, jointly with Robert fitz Stephen, with whom he divided it, a territory called the "Kingodom of Cork" (ie. the Gaelic Kingdom of Desmond, covering an area in what are now Counties Cork and Kerry, ruled by the MacCarthys); killed by a native Irish 1182, leaving an only daughter and heiress.  [Burke's Peerage]

Note: I do not know whether this is the same Milo de Cogan as described above.  The name, death date, and birth in Glamorganshire are all similar; as well as the Irish connection present in subsequent generations.  The Miles described above supposedly had no children, but in a preamble to the line Burke's states "Not merely the origins but the very nomenclature of this peerage are shrouded in mist."  Certainly the son William did not inherit any Irish lands.