Alexander I sealed his brother's renunciation of the throne in envelopes, Russia swore allegiance to the wrong heir, and the guards revolted

Under Paul I's succession law, the heir after Alexander I was his next brother, Grand Duke Constantine, who commanded the army in Poland. In 1820 Constantine divorced his German wife and married a Polish noblewoman, Joanna Grudzińska. On 14 January 1822 he wrote to Alexander renouncing his right to the throne. Alexander agreed on 2 February 1822, and on 16 August 1823 he signed a manifesto confirming their younger brother Nicholas as heir. The papers were sealed and deposited with the State Council, the Senate and the Holy Synod, to be opened at the emperor's death. Nothing was published. Alexander died at Taganrog on 1 December 1825. When the news reached St Petersburg, Nicholas swore allegiance to Constantine and had the regiments do the same. Constantine stayed in Warsaw, refused to come, and confirmed his renunciation only in writing. Russia had a sworn emperor who would not reign for about three weeks. The confirmation reached St Petersburg on 12 December and Nicholas issued his accession manifesto that day. On 14 December, when the guards were ordered to take a second oath, the Moscow regiment refused and marched to Senate Square calling for Constantine and a constitution. Governor-General Miloradovich was shot dead while trying to talk them down. After three volleys of grapeshot the rebels scattered. The Supreme Criminal Court tried 121 men. Five were hanged at the Peter and Paul Fortress on 13 July 1826. Constantine died of cholera at Vitebsk in 1831.