You will be given a definition of a task first, then an example. Follow the example to solve a new instance of the task.
In this task, you are given a question and a context passage. You have to answer the question based on the given passage.

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.
Solution: Russian Revolution
Why? This is a good example, and the Russian Revolution is the first event mentioned.

New input: Besides sending a ship to the Black Sea, what else prompted the creating of the treaty confirming that France and the Roman Catholic Church would be the supreme Christian authority?, Context: Napoleon III responded with a show of force, sending the ship of the line Charlemagne to the Black Sea. This action was a violation of the London Straits Convention.:104:19 Thus, France's show of force presented a real threat, and when combined with aggressive diplomacy and money, induced the Ottoman Sultan Abdülmecid I to accept a new treaty, confirming France and the Roman Catholic Church as the supreme Christian authority with control over the Roman Catholic holy places and possession of the keys to the Church of the Nativity, previously held by the Greek Orthodox Church.:20
Solution:
aggressive diplomacy and money