(Henry de), Lord of St Saife, and an eminent French writer, was descended from a very ancient and noble family, and born at St Saife in 1658. His education was among the fathers of the oratory; where he discovered from his infancy those uncommon abilities for which he was afterwards distinguished. He applied himself principally to the study of history; and his performances in this way are numerous and considerable. He was the author of a history of the Arabians; Fourteen letters upon the ancient parliaments of France; a History of France to the reign of Charles VIII.; the State of France, with historical memoirs concerning the ancient government of that monarchy, to the time of Hugh Capet, "written (says Mr Montesquieu) with a simplicity and honest freedom worthy of that ancient family from which their author was descended." Mr Boulainvilliers died at Paris in 1722; and after his death was published his Life of Mahomet.