Izuna, this place is a mess. We need to stop this war.
I know, but we are far too young and not strong enough.
I will end this constant cycle of hatred.
Madara was born a Demigod, with 4 brothers. Unfortunately, at the time of war, 3 of them died, leaving Madara with one brother left, named Izuna, whom he loved and clung to dearly.
During Madara's Childhood, he was at war. He and his brother, Izuna, wanted to protect everyone they could, although, they know they can do nothing of it. They leave the idea and ideology of peace alone for the time being.
During Battle, Izuna dies. Madara boils with hatred and revenge, and claims it. Madara now knows that he has to do something about the war. He seeks to put every mortal on earth in a coma, where their dreams come true, thus ending the war, and bringing true happiness. He names this project "Infinite Tsukuyomi". He dies of old age before this happens.
Madara is reanimated, and brought back to the world of the living. He reflects his eyes of the surface of the moon, and every mortal on Earth is now in a coma of their dreams. This ends the war, but the Gods above are not happy of Madara's decision.
Poseidon, the God of the Sea, drops from Mount Olympus to contest Madara's ideology. Madara is not up for the lecture, and engages in a long battle with Poseidon. Madara has great strength for a Demigod, but hardly looses to Poseidon. Madara dies once again, and the Infinite Tsukuyomi is ended. All mortals are free of their coma.
Madara now lives in Mount Olympus as a full God. He watches over the mortals of Earth, and he is responsible for comas.