Konstantin Pavlovich (; ) was a grand duke of Russia and the second son of Emperor Paul I and Sophie Dorothea of Württemberg. He was the heir-presumptive for most of his elder brother Alexander I's reign, but had secretly renounced his claim to the throne in 1823. For 25 days after the death of Alexander I, from 19 November (O.S.)/1 December 1825 to 14 December (O.S.)/26 December 1825 he was known as His Imperial Majesty Konstantin I Emperor and Sovereign of Russia, although he never reigned and never acceded to the throne. His younger brother Nicholas became tsar in 1825. The succession controversy became the pretext of the Decembrist revolt.
Konstantin was known to eschew court etiquette and to take frequent stands against the wishes of his brother Alexander I, for which he is remembered fondly in Russia, but in his capacity as the governor of Poland he is remembered as a hated ruler.
Early life
Konstantin was born in Tsarskoye Selo on 27 April 1779, the second son of the Tsesarevich Paul Petrovich and his wife Maria Fyodorovna, daughter of Friedrich II Eugen, Duke of Württemberg. Of all Paul's children, Konstantin most closely resembled his father both physically and mentally.
His paternal grandmother Catherine the Great named him after Constantine the Great, the founder of the Eastern Roman Empire. A medal with antique figures was struck to commemorate his birth; it bears the inscription "Back to Byzantium" which clearly alludes to Catherine's Greek Plan. According to the British ambassador James Harris,
The direction of the boy's upbringing was entirely in the hands of his grandmother, the empress Catherine II. As in the case of her eldest grandson (afterwards the emperor Alexander I), she regulated every detail of his physical and mental education; but in accordance with her usual custom, she left the carrying out of her views to the men who were in her confidence. Count Nikolai Saltykov was supposed to be the actual tutor, but he too in his turn transferred the burden to another, interfering personally only on exceptional occasions, and exercised no influence upon the character of the passionate, restless and headstrong boy. The only person who exerted a responsible influence was Cesar La Harpe, who was tutor-in-chief from 1783 to May 1795 and educated both the empress's grandsons.
Catherine arranged Konstantin's marriage as she had Alexander's; Juliane of Saxe-Coburg-Saalfeld, 14, and Konstantin, 16, were married on 26 February 1796. As Caroline Bauer recorded in her memoirs, "The brutal Constantine treated his consort like a slave. So far did he forget all good manners and decency that, in the presence of his rough officers, he made demands on her, as his property, which will hardly bear being hinted of." Due to his violent treatment and suffering health problems as a result, Juliane separated from Konstantin in 1799; she eventually settled in Switzerland. An attempt by Konstantin in 1814 to convince her to return broke down in the face of her firm opposition.
Napoleonic Wars
During this time, Konstantin's first campaign took place under the leadership of Suvorov. The battle of Bassignana was lost by Konstantin's fault; but at Novi he distinguished himself by personal bravery, so that the emperor Paul bestowed on him the title of tsesarevich, which according to the fundamental law of the constitution belonged only to the heir to the throne. Though it cannot be proved that this action of the tsar denoted any far-reaching plan, it yet shows that Paul already distrusted the grand-duke Alexander.
Konstantin never tried to secure the throne. After his father's death in 1801, he led a disorderly bachelor life. He abstained from politics, but remained faithful to his military inclinations, without manifesting anything more than a preference for the externalities of the service. In command of the Imperial Guards during the campaign of 1805, he had a share of the responsibility for the Russian defeat at the battle of Austerlitz; while in 1807 neither his skill nor his fortune in war showed any improvement.
After the peace of Tilsit he became an ardent admirer of Napoleon and an upholder of the Russo-French alliance. He therefore lost the confidence of his brother Alexander; to the latter, the French alliance was merely a means to an end. This view was not held by Konstantin; even in 1812, after the fall of Moscow, he pressed for a speedy conclusion of peace with Napoleon, and, like field marshal Kutuzov, he too opposed the policy which carried the war across the Russian frontier to victorious conclusion upon French soil. His personal behaviour towards both his own men and French prisoners was eccentric and cruel.