Bloody Sunday or Red Sunday is the name given to the events of Saturday, 22 January [O.S. 9 January] 1905 in St Petersburg, Russia, when unarmed demonstrators, led by Father Georgy Gapon, are fired upon by soldiers of the Imperial Guard as they march towards the Winter Palace to present a petition to Tsar Nicholas II of Russia.
Bloody Sunday causes grave consequences for the Tsarist autocracy governing Imperial Russia: the events in St. Petersburg provoke public outrage and a series of massive strikes that spreads quickly to the industrial centers of the Russian Empire.
The massacre on Bloody Sunday is considered to be the start of the active phase of the Revolution of 1905.