Answer based on context:

Despite its occurrence at the height of World War I, the roots of the February Revolution date further back. Chief among these was Imperial Russia's failure, throughout the 19th and early 20th century, to modernize its archaic social, economic and political structures while maintaining the stability of ubiquitous devotion to an autocratic monarch. As historian Richard Pipes writes, "the incompatibility of capitalism and autocracy struck all who gave thought to the matter". The first major event of the Russian Revolution was the February Revolution, which was a chaotic affair, caused by the culmination of over a century of civil and military unrest. There were many causes of this unrest of the common people towards the Tsar and aristocratic landowners. The causes can be summarized as the ongoing cruel treatment of peasants by the bourgeoisie, poor working conditions of industrial workers and the spreading of western democratic ideas by political activists. All of these causes led to a growing political and social awareness in the lower classes of Russia. Dissatisfaction of proletarians was compounded by food shortages and military failures. In 1905, Russia experienced humiliating losses in its war with Japan, then Bloody Sunday and the Revolution of 1905, in which Tsarist troops fired upon a peaceful, unarmed crowd, further dividing Nicholas II from his people. Widespread strikes, riots and the famous mutiny on the Battleship Potemkin ensued. These conditions caused much agitation among the small working and professional classes. This tension erupted into general revolt with the 1905 Revolution, and again under the strain of war in 1917, this time with lasting consequences.

Which event was a chaotic affair?
the Revolution