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: What was the follow up to the Empire of Britain?, Context: The ability of the Dominions to set their own foreign policy, independent of Britain, was recognised at the 1923 Imperial Conference. Britain's request for military assistance from the Dominions at the outbreak of the Chanak Crisis the previous year had been turned down by Canada and South Africa, and Canada had refused to be bound by the 1923 Treaty of Lausanne. After pressure from Ireland and South Africa, the 1926 Imperial Conference issued the Balfour Declaration, declaring the Dominions to be "autonomous Communities within the British Empire, equal in status, in no way subordinate one to another" within a "British Commonwealth of Nations". This declaration was given legal substance under the 1931 Statute of Westminster. The parliaments of Canada, Australia, New Zealand, the Union of South Africa, the Irish Free State and Newfoundland were now independent of British legislative control, they could nullify British laws and Britain could no longer pass laws for them without their consent. Newfoundland reverted to colonial status in 1933, suffering from financial difficulties during the Great Depression. Ireland distanced itself further from Britain with the introduction of a new constitution in 1937, making it a republic in all but name.
Solution:
British Commonwealth of Nations