The October Revolution was the second revolution that took place in Russia in 1917. In February 1917, revolutionaries in St. Petersburg, overthrew the Tsar resulting in his abdication and the end of the Romanov dynasty and the Russian Empire. Russian was put under the control of a provisional government under Prince Georgy Lvov.
After the February Revolution, ‘Soviets’ were created across Russia. The Soviets were worker’s councils, popular due to disaffection with the ability of the provisional government to improve the conditions of workers.
Many leaders of the Soviets were Bolsheviks, which strengthened the Bolsheviks in Russia to the point, under the leadership of Lenin, they initiated the October Revolution, an armed insurrection in Petrograd on November 7th 1917. This revolution established the Russian Socialist Federative Soviet Republic, the world’s first self-proclaimed socialist state.
You may have noticed this holiday is called October Revolution Day yet celebrates an event that took place in November. The reason is that in 1917, Russia was still using the Julian calendar which was 12 days behind the Gregorian calendar at that time, so the revolution took place on October 25th.
Belarus is the only country that was part of the Soviet Union that still observes a public holiday to mark the October Revolution.
During the period of the Soviet Union, November 7th was a public holiday across the union and was one of the biggest state celebrations of the year.
In Russia, the day is a normal working day. The public holiday has been replaced by National Unity Day, celebrated on November 4th.