Bloody Sunday in Saint Petersburg, beginning of the 1905 revolution.

Bloody Sunday, also known as Red Sunday, was the series of events on Sunday, 22 January [O.S. 9 January] 1905 in St Petersburg, Russia, when demonstrators, led by Father Georgy Gapon, were fired upon by soldiers of the Imperial Guard as they marched towards the Winter Palace to present a petition to Tsar Nicholas II.

Saint Petersburg, formerly known as Petrograd and later Leningrad, is the second-largest city in Russia after Moscow. It is situated on the River Neva, at the head of the Gulf of Finland on the Baltic Sea. With an area of 1,439 sq km, Saint Petersburg is the smallest administrative division of Russia by area. The city had a population of 5,601,911 residents as of 2021, with more than 6.4 million people living in the metropolitan area. Saint Petersburg is the fourth-most populous city in Europe, the most populous city on the Baltic Sea, and the world's northernmost city of more than 1 million residents. As the former capital of the Russian Empire, and a historically strategic port, it is governed as a federal city.

The Russian Revolution of 1905, also known as the First Russian Revolution, was a revolution in the Russian Empire which began on 22 January 1905 and led to the establishment of a constitutional monarchy under the Russian Constitution of 1906, the country's first. The revolution was characterized by mass political and social unrest including worker strikes, peasant revolts, and military mutinies directed against Tsar Nicholas II and the autocracy, who were forced to establish the State Duma legislative assembly and grant certain rights, though both were later undermined.