The Ulster chiefs had been directly subordinate to de Lacy, but he died before February 1243, and his earldom reverted to the crown, presumably because of the unrecorded terms on which it had been restored to him, for he left at least one daughter, the wife of David fitz William, baron of Naas."------A. J. Othway-Ruthven, History of Medieval Ireland, 2nd Ed., Barnes & Noble 1980, p. 100.