In this task, you are given a question and a context passage. You have to answer the question based on the given passage.

Let me give you an example: what is the first event mentioned?, Context: The Russian Revolution is the series of revolutions in Russia in 1917, which destroyed the Tsarist autocracy and led to the creation of the Soviet Union. Following the abdication of Nicholas II of Russia, the Russian Provisional Government was established. In October 1917, a red faction revolution occurred in which the Red Guard, armed groups of workers and deserting soldiers directed by the Bolshevik Party, seized control of Saint Petersburg (then known as Petrograd) and began an immediate armed takeover of cities and villages throughout the former Russian Empire.
The answer to this example can be: Russian Revolution
Here is why: This is a good example, and the Russian Revolution is the first event mentioned.

OK. solve this:
__ began in Khitrivo, Context: The principal fighting occurred between the Bolshevik Red Army and the forces of the White Army. Many foreign armies warred against the Red Army, notably the Allied Forces, yet many volunteer foreigners fought in both sides of the Russian Civil War. Other nationalist and regional political groups also participated in the war, including the Ukrainian nationalist Green Army, the Ukrainian anarchist Black Army and Black Guards, and warlords such as Ungern von Sternberg. The most intense fighting took place from 1918 to 1920. Major military operations ended on 25 October 1922 when the Red Army occupied Vladivostok, previously held by the Provisional Priamur Government. The last enclave of the White Forces was the Ayano-Maysky District on the Pacific coast. The majority of the fighting ended in 1920 with the defeat of General Pyotr Wrangel in the Crimea, but a notable resistance in certain areas continued until 1923 (e.g., Kronstadt Uprising, Tambov Rebellion, Basmachi Revolt, and the final resistance of the White movement in the Far East).
Answer:
Tambov Rebellion