Perhaps the main thing which led to the collapse of the Tsarist regime was the First World War. If the Tsar’s government before 1914 was weak, the war pushed it to breaking point. The war took men from the farms and food to the front, and it clogged up the railway system, so that people starved in the towns. Prices rose, and there was famine in the winter of 1916-1917.
Huge Russian defeats at Tannenberg and the Masurian Lakes made the government look incompetent, especially when Tsar Nicholas insisted in taking personal charge of the army. In the meantime, the army which was needed to keep control of the people became disillusioned and rebellious. Back in St Petersburg, Nicholas left the government in the hands of the Tsarina, who was completely in the power of Rasputin. The nobles who had supported the monarchy found themselves humiliated. The Church was scandalised.
In March 1917, things reached a head. Many workers went on strike. On 8 March, marches held as part of International Women’s Day got out of hand and turned into riots. At first troops fired on the crowds, but on 12 March they mutinied and joined the rioters. That same day the Duma also deserted the Tsar and set up a ‘provisional government’. That same day, also, the workers and soldiers of St Petersburg set up a Soviet of 2500 elected deputies.
Too late, the Tsar got on a train. He did not even manage to return to St Petersburg; members of the Duma met him and forced him abdicate. He had been toppled by a popular revolution, and the people rejoiced in the streets.