any of the Russian revolutionaries who led an unsuccessful uprising on Dec. 14 (Dec. 26, New Style), 1825, and through their martyrdom provided a source of inspiration to succeeding generations of Russian dissidents. The Decembrists were primarily members of the upper classes who had military backgrounds; some had participated in the Russian occupation of France after the Napoleonic Wars or served elsewhere in western Europe; a few had been Freemasons, and some were members of the secret patriotic (and, later, revolutionary) societies in Russia—the Union of Salvation (1816), the Union of Welfare (1818), the Northern Society (1821), and the Southern Society (1821).

The Northern Society, taking advantage of the brief but confusing interregnum following the death of Tsar Alexander I, staged an uprising, convincing some of the troops in St. Petersburg to refuse to take a loyalty oath to Nicholas I and to demand instead the accession of his brother Constantine. The rebellion, however, was poorly organized and easily suppressed; Colonel Prince Sergey Trubetskoy, who was to be the provisional dictator, fled immediately.

Another insurrection by the Chernigov regiment in the south was also quickly defeated. An extensive investigation in which Nicholas personally participated ensued; it resulted in the trial of 289 Decembrists, the execution of 5 of them (Pavel Pestel, Sergey Muravyov-Apostol, Pyotr Kakhovsky, Mikhail Bestuzhev-Ryumin, and Kondraty Ryleyev), the imprisonment of 31, and the banishment of the rest to Siberia.