Answer:
Assassination of Alexander II of Russia
Defeat in the Russo-Japanese War
Bloody Sunday
Step-by-step explanation:
The Russian Revolution, which began with the 'February Revolution' of 1917 and ended with the 'October Revolution' later that year, led to the fall of the Russian Empire and the establishment of the Soviet Union (in 1922). It was the outcome of a protracted period of economic hardship, social upheaval, and political repression that began in the late 19th and early 20th centuries. The events covered here did not start the Russian Revolution, but each one drove the nation closer to the tipping point.
The last Russian Tsar, Nicholas II (reigned from 1894 to 1917), continued his predecessor's reactionary policies, which exacerbated sociopolitical turmoil and aided radical revolutionary movements in gaining ground.
Russia and Japan's disagreement over Manchuria and Korea erupted into a war in 1904. The radicalization of the workers and peasants, who had previously looked up to the tsar as their "father" and protector, was another consequence of Bloody Sunday. The tsar abruptly changed into a brutal autocrat.
Thus, the St. Petersburg Massacre aided in preparing the ground for the 1917 Revolution.
I hope I have answered your question in a correct way possible.