Constantine Pavlovitch, grand duke of Russia, son of the emperor Paul I., younger brother of Alexander I., and elder brother of Nicholas, born in St. Petersburg, May 8, 1779, died at Vitebsk, June 27, 1831. His grandmother, Catharine II., is said to have destined him to reign over a new empire of the East, in accordance with a popular prophecy that a Constantine should rule again at Constantinople, and attempted to educate him with that view; but he was a wilful and capricious youth, and cared for nothing but military exercises. At the age of 17 he married the princess Juliana of Saxe-Coburg, but after some years of unhappiness she left him and returned to Germany. He accompanied Suvaroff to Switzerland in 1799, and subsequently had a command at Austerlitz, and fought in several battles in the struggle with France, displaying bravery, but little skill as a commander. The duchy of Warsaw having been given to Russia by the congress of Vienna, and transformed by Alexander into a constitutional kingdom of Poland in 1815, he was made commander-in-chief of the Polish forces, with powers which made him the virtual ruler, though Zajonczek was the nominal viceroy. He gave the army a thorough discipline, but his capricious severity alienated from him the most distinguished of its officers.

In 1820 he conceived a violent passion for a Polish lady, the countess Johanna Grudzinska, and through the intercession of the emperor obtained a divorce from the princess of Saxe-Coburg, with permission to marry again. In return he formally renounced for himself and his descendants the right of succession to the crown. The document containing this renunciation was kept secret until the death of Alexander in 1825, when, though actually proclaimed emperor by a revolutionary party at St. Petersburg, Constantine insisted upon maintaining his renunciation, and assisted at the coronation of Nicholas, who was 17 years his junior. He continued in command at Warsaw, where his violent measures constantly fomented the anti-Eussian feelings of the Poles. Four months after the breaking out of the French revolution of 1830 he was driven from Warsaw by an insurrection, and took a command in the Russian army under Diebitsch which was sent to reduce the country to subjection, but disgusted the Russians by the lack of zeal he evinced. Being recalled by the emperor, he retired to Bialystok, but was soon driven away by the Poles under Chlapowski, his brother-in-law, and not long after died of cholera.

His wife, who had been made princess of Lowicz, survived him but a few months.