He was born in
Paris into a wealthy
Jansenist family and was educated at the
Petites écoles of
Port-Royal, where his historical interests were formed and encouraged. At the age of twenty, he began his two monumental works, the ''Mémoires pour servir à l'histoire ecclésiastique des six premiers siècles
and the Histoire des empereurs et autres princes qui ont régné pendant les six premiers siècles de l'Église''. The first is a history of the first six centuries of the Christian Church. The second is a history of the Roman emperors during the same period. Tillemont became a priest at the age of 39 and settled at Port-Royal. When Port-Royal was dissolved in 1679, he moved to his family estate at Tillemont, where he spent the rest of his life, pursuing his historical work with great devotion. His
Histoire began to issue from the press in 1690 and his
Mémoires in 1693. The publication of both works was not complete at the time of his death. The final volumes were completed and published posthumously by his secretary
Michel Tronchay. Tronchay also published a biography of Tillemont in 1706 titled ''Idee de la vie et de l'esprit de M. L. de Tillemont''. Tillemont is cited frequently by
Edward Gibbon in his
Decline and Fall of the Roman Empire. Tillemont's works were among the first to provide critical surveys of the full range of source material. His prose style is considered dry, but he had a reputation for accuracy, detail and conscientiousness. His work was attacked on a large scale by
Honoratus a Sancta Maria in his three-volume ''Réflexions sur les règles et l'usage de la critique'' (1712–1720). ==Selected works==