In March of 1917, food shortages and civil unrest led to the abdication of Czar Nicholas II. Months later, the provisional government was overthrown by the Bolsheviks, led by Vladimir Lenin.
Czar Nicholas II was executed by Bolshevik forces in July of 1918. The Bolsheviks were committed to the ideas of Karl Marx, and they believed that the working classes would free themselves from the economic and political control of the ruling class. They wanted to form a socialist society based on equality. The provisional government was never elected, and it chose to remain in World War I, despite the fact that the country was ill-equipped to fight against Germany. This made people more in favor of the revolution.