According to Homer's "The Iliad"
This started the Trojan War when the Greeks launched a thousand ships to attack Troy. Helen is known as "the face that launched a thousand ships".
According to Homer the war began from around 1750 BCE to around 1300 BCE.
When Eris throws a golden apple with the words "For the Fairest" inscribed in them, thus incurring a conflict between three goddesses and Paris, a Trojan prince.
Achilles is outraged that Hector killed his best friend, Patroclus, so he gets revenge by killing him and defiling his body.
Patroclus dies by Hector's hand, throwing Achilles into a fit of rage and launching back into the war.
After days of Hector's body being mutilated by Achilles, Priam ventures to the Greek camp to plead for his son's body to be spared. Achilles and Priam grieve together and eventually Achilles allows Priam to take Hector's body home to be properly buried.
The Trojan Horse is used to trick the Trojans, therefore allowing the Greeks into Troy and thus came a victory for the Greeks.