Francis I. (Stephen), emperor of Germany, born Dec. 8, 1708, died at Innspruck, Aug. 18, 1765. He was the son of Leopold, duke of Lorraine, and of a niece of Louis XIV., and was the great-grandson of the emperor Ferdinand III. In 1729 he succeeded his father, but in consequence of the war of the Polish succession, his duchy was given in 1735 to the ex-king Stanislas, father-in-law of Louis XV., to revert after his death to France, and he received the reversion of the duchy of Tus-cany, where the house of Medici was about becoming extinct. Francis in 1736 married Maria Theresa, daughter and heiress of the emperor Charles VI. Charles appointed him generalissimo, and he subsequently fought in a successful campaign against the Turks. After the death of the last of the Medicis in 1737, Francis went with Maria to Florence, the capital of his new dominion. The emperor dying in 1740, he returned to share with his wife the regency of the Austrian dominions, though without any real power in the administration, and fought for her rights in the wars which ensued.

Francis was elected emperor of Germany in 1745, and acknowledged by Bavaria and Prussia in the same year, but not by France and Spain until the peace of Aix-la-Chapelle in 1748. Being of a mild and peaceful disposition, and influenced more by avarice than by ambition, he promoted commerce and agriculture, particularly in Tuscany, but left the heavier cares of government to his wife, who in 1756 became involved in the seven years' war with Prussia. Two years after the termination of this war Francis died, leaving the German crown to his son Joseph II., for whom, however, his mother reigned till 1780, and Tuscany to his younger son, afterward Leopold II.