Answer:
The Trojan War, in Greek tradition, started as a way for Zeus to reduce the ever-increasing population of humanity and, more practically, as an expedition to reclaim Helen, wife of Menelaus, King of Sparta and brother of Agamemnon.
Explanation:
According to the ancient Greek epic poet Homer, the Trojan War was caused by Paris, son of the Trojan king, and Helen, wife of the Greek king Menelaus, when they went off together to Troy. To get her back, Menelaus sought help from his brother Agamemnon, who assembled a Greek army to defeat Troy.