lawyer, educator, and historian who was the leader of the French Protestant refugees in Germany.

Born of a distinguished family of French Protestants, Ancillon studied law at Marburg, Geneva, and Paris. He pleaded the cause of the Huguenots—the French Protestants—of Metz at the court of Louis XIV, urging that an exception be made for them in the revocation of the Edict of Nantes (1685). Ancillon's efforts were unsuccessful, however, and he moved to Berlin, where he was appointed by Frederick III, the elector of Brandenburg, as judge of the French refugees in that state. Made director in 1687 of the Academy of Nobles, the principal educational establishment of the state, he cooperated with the German philosopher Gottfried Wilhelm Leibniz in the founding of the Academy of Berlin, a society of arts and sciences.

Appointed historiographer to the elector in 1699, Ancillon replaced, in the same year, his uncle, Joseph Ancillon, as judge of all the French refugees. As councillor of embassy at the imperial court, he was involved in the negotiations that resulted in the election of Frederick the Elector to be king in 1701 as Frederick I. His works include the Histoire de l'établissement des français réfugiés dans les états de S.A.E. Brandenbourg (1690; “The History of the Establishment of the French Refugees in Brandenburg State”) and L'Irrévocabilité de l'édit de Nantes (1688; “The Irrevocability of the Edict of Nantes”).