Teacher: In this task, you are given a question and a context passage. You have to answer the question based on the given passage.
Teacher: Now, understand the problem? If you are still confused, see the following 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.
Solution: Russian Revolution
Reason: This is a good example, and the Russian Revolution is the first event mentioned.

Now, solve this instance: Prior to his death who did Alexander the third defeat completely?, Context: Following the assassination of Phillip II, his son Alexander III ("The Great") assumed the leadership of the League of Corinth and launched an invasion of the Persian Empire with the combined forces of all Greek states in 334 BC. Undefeated in battle, Alexander had conquered the Persian Empire in its entirety by 330 BC. By the time of his death in 323 BC, he had created one of the largest empires in history, stretching from Greece to India. His empire split into several kingdoms upon his death, the most famous of which were the Seleucid Empire, Ptolemaic Egypt, the Greco-Bactrian Kingdom and the Indo-Greek Kingdom. Many Greeks migrated to Alexandria, Antioch, Seleucia and the many other new Hellenistic cities in Asia and Africa. Although the political unity of Alexander's empire could not be maintained, it resulted in the Hellenistic civilization and spread the Greek language and Greek culture in the territories conquered by Alexander. Greek science, technology and mathematics are generally considered to have reached their peak during the Hellenistic period.
Student:
the Persian Empire