Isaac De Beausobre, a French Protestant theologian, born at Niort in Poitou in 1859, died in Berlin in 1738. He studied theology at the academy of Saumur, and was ordained by the synod of Loudun in 1683. He assumed the charge of the Calvinist church at Chatillon-sur-Indre, and was obliged to close his place of worship upon the revocation of the edict of Nantes in 1685, but continued to hold meetings of his congregation at his own house until threats of imprisonment compelled him to leave France. He took refuge in Holland, where he was appointed private chaplain to the princess of Anhalt-Dessau, a daughter of the dowager princess of Orange. On the death of the husband of his patroness, he changed his residence to Berlin in 1694, and was appointed pastor of a French Protestant church there, and in 1707 a member of the consistory, a position which he held till his death. He also acted for many years as inspector of the French schools and churches of the city. He was the principal contributor to the Bibliotheque allemande, begun in 1720, of which 50 volumes were published, and was one of the editors of the Journal d'Allemagne, de Suisse et du Nord (new ed., 2 vols. 8vo, the Hague, 1741-'3). He wrote a "Defence of the Doctrines of the Reformers" (1694); an unfinished history of the reformation (Berlin, 1785; translated into English, 1802); with L'Enfant, a French translation of the New Testament (Amsterdam, 1718), and two volumes of commentaries upon it.

Among his numerous historical and theological works of less importance are his Histoire de Manichee et du Manicheisme (Amsterdam, 1734-'9), and Sujjplement a l'histoire des Hussites (Lausanne, 1745). His sermons were collected and published after his death (3d ed., 4 vols., Lausanne, 1758).