The longest poem ever written is "The Mahabharata" by Vyasa the respected Hindu figure. He was believed to be the incarnation of the Hindu god Vishnu. The Mahabharata is 10 times longer than the Iliad and Odyssey combined. It has over 1.8 million words and more than 100,000 verses.
Written in 300 B.C.E., the Mahabharata tells the story of the Kurukshetra War in which two factions of cousins, the Kaurava and the Pandava princes, fought for the right to ascend the throne of a dynasty. The war lasted 18 days and came to involve the rest of the Indian ruling families. Although there are historical claims to the war, there is no conclusive evidence that it really took place in history.