STANISLAUS I. IL (1677-1766), king of Po land, born at Lemberg in 1677, was the son of Rafael Leszczynski, palatine of Posen, and Anne Catherine Jablonowska. He married Catherine Opalinska by whom he had one daughter. In 1697, as cupbearer of Poland, he signed the confirmation of the articles of election of Augustus II. In 1703 he joined the Lithuanian Con federacy against Augustus, and in the following year Charles XII. selected him to supersede Augustus, and by bribery and intimida tion secured his election (July 2, 1704). A few months later Stanislaus was forced by a sudden inroad of Augustus to seek refuge in the Swedish camp, but finally on Sept. 24, 1705, was crowned king with great splendour. Stanislaus at once concluded an alliance with Charles, and rendered him some small assistance against the tsar; but he depended entirely on the success of his ally's arms, and after Poltava (17°9) the vast majority of the Poles hastened to repudiate him and make their peace with Augus tus, and Leszczynski, henceforth a mere pensioner of Charles XII., retreated to Swedish Pomerania. On the restoration of Augustus, Stanislaus resigned the Polish Crown (though he retained the royal title) in exchange for the little principality of Zweibriicken, residing at Weissembourg in Lorraine.
In 1725 Louis XV. of France married Stanislaus' daughter Mary, and supported his claims to the Polish throne after the death of Augustus II. in 1733, which led to the war of the Polish Succession. On Sept. 9 1733 Stanislaus himself arrived at Warsaw,
having travelled through central Europe disguised as a coachman, and on the loth was once more elected king of Poland. Russia, however, protested, proclaimed the Saxon candidate king as Augustus III. (June 30, and in October besieged Stanislaus with his partisans in Danzig. The expected French help did not arrive until May 20, 1735, when a fleet disembarked a small force, which, however, could do little. On June 3o Danzig capitulated unconditionally after a stubborn resistance of 135 days. Stanis laus, disguised as a peasant, had contrived to escape two days before. He attempted to rally his partisans from Konigsberg, and to secure fresh help from France and from Count Potocki in the Ukraine, but without avail.
In 1736 Stanislaus again abdicated the throne, but received by way of compensation the dukedom of Lorraine and Bar, which was to revert to France on his death. He settled at Luneville, founded there the Academia Stanislai, and devoted himself for the rest of his life to science and philanthropy. He died in 1766 at the age of 89. Among his works may be mentioned: Oeuvres du philosophe bienfaisant (Paris, 1763 ; 1866).
See Robert Nisbet Bain, Charles X//. (1895) ; Louis Lacroix, Les Opuscules inedites de S. L. (Nancy, 1866) ; Lettres inedites de S. L., ed. P. Boye (1905) ; Marchioness Des Reaulx, Le Roi Stanislas et Marie Leszczynski (1895).