Constantine, the eldest brother of Alexander I., had relinquished his right to the crown, thus breaking the regular succession.  From the time of Paul a revolutionary party had existed, and once at least it plotted the assassination of Alexander.  There was an interregnum of three weeks between the death of Alexander and the assumption of power by his second brother, Nicholas.  The change of succession strengthened the revolutionists, and they employed the interregnum to organize a conspiracy for seizing the government.

The conspiracy was wide spread, and included many of the ablest men of the day.  The army was seriously implicated.  The revolutionists desired a constitutional government, and their rallying cry of “CONSTITUTIA!” was explained to the soldiers as the name of Constantine’s wife.  The real design of the movement was not confided to the rank and file, who supposed they were fighting for Constantine and the regular succession of the throne.

Nicholas learned of the conspiracy the day before his ascension; the Imperial guard of the palace was in the plot, and expected to seize the emperor’s person.  The guard was removed during the night and a battalion from Finland substituted.  It is said that on receiving intelligence of the assembling of the insurgents, the emperor called his wife to the chapel of the palace, where he spent a few moments in prayer.  Then taking his son, the present emperor, he led him to the soldiers of the new guard, confided him to their protection, and departed for St. Isaac’s Square to suppress the revolt.  The soldiers kept the boy until the emperor’s return, and would not even surrender him to his tutor.

The plot was so wide-spread that the conspirators had good promise of success, but whole regiments backed out at the last moment and left only a forlorn hope to begin the struggle.  Nicholas rode with his officers to St. Isaac’s square, and twice commanded the assembled insurgents to surrender.  They refused, and were then saluted with “the last argument of kings.”  A storm of grape shot, followed by a charge of cavalry, put in flight all who were not killed, and ended the insurrection.

A long and searching investigation followed, disclosing all the ramifications of the plot.  The conspirators declared they were led to what they undertook by the unfortunate condition of the country and the hope of improving it.  Nicholas, concealed behind a screen, heard most of the testimony and confessions, and learned therefrom a wholesome lesson.  The end of the affair was the execution of five principal conspirators and the banishment of many others to Siberia.  The five that suffered capital punishment were hanged in front of the Admiralty buildings in St. Petersburg.  One rope was broken, and the victim, falling to the ground, suffered such agony that the officer in charge of the execution sent to the emperor asking what to do.  “Take a new rope and finish your duty,” was the unpitying answer of Nicholas.