Bloody Sunday (Russia), massacre of peaceful demonstrators by members of the Russian Imperial Guard in Saint Petersburg on January 9 (or January 22, in the Western, or Gregorian, calendar), 1905, when some 200,000 workers gathered outside the Winter Palace, residence of Russian emperor Nicholas II. They intended to appeal directly to the emperor for better pay and conditions, following the failure of numerous organized strikes at the end of 1904. The demonstrators carried religious icons and pictures of Nicholas to show their peaceful intent. They were led by a priest, Georgy Apollonovich Gapon, who was also the leader of a workers’ organization.

Nicholas was absent at the time, but his uncle, Grand Duke Vladimir, commander of the Imperial Guard, gave the order to fire on the crowd. More than 100 of the demonstrators were killed, and many more were wounded. News of the massacre soon spread, provoking strikes in numerous cities, peasant uprisings in the countryside, and mutinies in the armed forces. This became known as the Russian Revolution of 1905.

In 1906 Nicholas attempted to appease the protesters by introducing Russia’s first elected legislative assembly, the Duma. Mass opinion had, however, been radicalized by the massacre and ensuing violence. Socialist parties, workers, and peasants continued to agitate against the imperial regime, culminating in the overthrow of the monarchy in the Russian Revolution of 1917.