FREDERICK I. (1657-1713), the first king of Prussia, was born at Konigsberg, 1657. He was the son of the Great Elector by his first marriage. In consequence of a fall from the arms of his nurse his spine was so seriously injured that he was deformed for life. His stepmother intrigued against him incessantly in the interests of her children; and she succeeded in persuading her husband to make a will whereby Frederick should receive only the electoral title and the electoral lands, the remaining territories being divided among his half-brothers. On his accession in 1688 this will was set aside, with the sanction of the emperor, whose support he had obtained beforehand by signing away in his father's lifetime his rights in Schwiebus, a proceeding which, he afterwards maintained, restored his claim to the Silesian principalities. Frederick, having a strong love of pomp and show, strove hard to make his court an imitation of that of Louis XIV. Although without his father's firmness and energy, he seized every occasion of increasing his dominions by purchase ; and he obtained, partly in virtue of certain claims inherited from his mother, partly through the influence of William III. of England, the principality of Neufchatel. It had been the intention of the Great Elector to give William III. vigorous support both in his struggle for the English crown and in the wars with France which were seen to be inevitable. Frederick gave effect to this purpose, and his troops played an important part in the battle of the Boyne. In the course of his reign he exercised considerable influence on European politics by placing auxiliary forces at the disposal of friendly princes. The accession of Augustus the Strong of Saxony to the throne of Poland fired his ambition, and for years he endeavoured to induce the emperor Leopold I. to recognize him as king of Prussia. At last, in November 1700, the emperor consented, insisting, however, on various strict conditions, one of which was that in the approaching war of the Spanish succession Prussia should contribute a force of 10,000 men to the Austrian army. Immediately after receiving the imperial sanction, Frederick started with his whole court for Konigsberg, where, on January 18, 1701, with much ceremony he crowned himself. He sent 20,000 men into the war of the Spanish succession, and a portion of them did excellent service at the battle of Blenheim. In 1706 Prince Leopold of Dessau led 6000 Prussians to victory at Turin. Frederick died on the 25th February, 1713. By his extravagance he not only exhausted the treasure amassed by his father, but burdened his country with heavy taxes. He was not, however, an unpopular sovereign, and by making Prussia a kingdom he undoubtedly advanced it several stages towards its future greatness. He founded the university of Halle and the Berlin Academy of Sciences, and was fond of protecting enlightened men who suffered persecution.

He was three times married, his second wife, Sophie Charlotte, sister of George I. of England, being well known as the friend of Leibnitz and as one of the most cultivated princesses of the age.

See Pnffendorf, Dc rebus yestis Frideriei III. (Berlin, 1731); W. Hahn, Friedrich, der erste KOnig ton Preussen (3d ed., Berlin, 1876); Carlyle, History of Friedrich H. of Prussia.