Pierre Helyot, a French historian, born in Paris in 1660, died Jan. 5, 1716. He was descended from an English Catholic family that took refuge in France, and in 1683 entered the third order of St. Francis in the convent of Picpus at Paris as Pere Hippolyte. He was twice sent to Rome on affairs of his order, and there projected the work by which he is best known, a history of the various religious orders. He was assisted in his researches by Anquetil, Hardouin, Mabillon, Ruinart, and other scholars. Two volumes were published in 1714 (4to, Paris), entitled Histoire des ordres monastiques, religieux et militaires, et des congregations se-culieres de l'un et de l'autre sexe. The six remaining volumes appeared in 1715, 1718, and 1719. It was reprinted in 1721 and 1792. An inferior edition, edited by Philippon de la Madeleine, appeared at Paris in 1838; and an edition in five volumes in Migne's Encyclopedie theologique, with a continuation to the time of publication (5 vols., Paris, 1847). The volumes that appeared after Helyot's death were edited by Maximilian Bullot. Helyot wrote also Le Chretien mourant (Paris, 1705).