Louis-Sébastien Le Nain de Tillemont

Louis-Sébastien Le Nain de Tillemont (30 November 1637 – 10 January 1698), ecclesiastical historian, came from a wealthy Jansenist family.

He was born in Paris, 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 thirty-nine 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 single-minded devotion. His "Histoire" began to issue from the press in 1690 and his "Mémoires" in 1693, though the publication of both works was not completed until after his death.

Tillemont is cited frequently by Gibbon in his "Decline and Fall of the Roman Empire". His 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.