The Decembrists (from Russian dekabr', “December”) were the mainly noble rebels who carried out an unsuccessful coup in St. Petersburg on December 14, 1825 (this and all subsequent dates according to the Old Style, i.e. the Julian Calendar). Some 3,000 officers and soldiers were ordered to muster in the Senate Square to swear an oath of allegiance to the new Tsar, Nicholas I. On this day, the Decembrists attempted to exploit confusion over the succession following the death of Tsar Alexander I (November 19, 1825), and persuade the assembled troops to …