The Columbia Encyclopedia, Sixth Edition. 2001-07.
Dermot McMurrough
or Diarmiud mac Murchada (both: dûr´mt mkmr´) (KEY) , 111071, Irish king of Leinster. He became involved in a complicated feud, partly because he abducted a neighbors wife, and in 1166 was defeated and banished by the High King Rory OConnor. Dermot appealed for help to Henry II of England, who refused him direct support but allowed him to enlist a force led by Richard de Clare, 2d earl of Pembroke, and other Norman barons in Wales. After Pembroke had invaded (1170) and won much of E Ireland, including Dublin, he married Dermots daughter, Eva. He was a patron of the compilation of the valuable Irish manuscript, the Book of Leinster.