The October Revolution, which gets its name from the Julian calendar date of 25 October, occurs, according to the Gregorian calendar; on this date, the Bolsheviks storm the Winter Palace.

The October Revolution, also known as the Great October Socialist Revolution, October coup, Bolshevik coup, or Bolshevik revolution, was the second of two revolutions in Russia in 1917. It was led by Vladimir Lenin's Bolsheviks as part of the broader Russian Revolution of 1917–1923. It began through an insurrection in Petrograd on 7 November 1917 [O.S. 25 October]. It was the precipitating event of the Russian Civil War. The initial stage of the October Revolution, which involved the assault on Petrograd, occurred largely without any casualties.

October 25 is the 298th day of the year in the Gregorian calendar; 67 days remain until the end of the year.

The Winter Palace is a palace in Saint Petersburg that served as the official residence of the House of Romanov, previous emperors, from 1732 to 1917. The palace and its precincts now house the Hermitage Museum. The floor area is 233,345 square metres. The total area of the Winter Palace is 14.2 hectares. Situated between Palace Embankment and Palace Square, adjacent to the site of Peter the Great's original Winter Palace, the present and fourth Winter Palace was built and altered almost continuously between the late 1730s and 1837, when it was severely damaged by fire and immediately rebuilt. The storming of the palace in 1917, as depicted in Soviet art and in Sergei Eisenstein's 1928 film October, became a symbol of the October Revolution.