The 500 Year War was a conflict between the Kingdoms of Heaven and Hell that took place mostly on Earth. It lasted from the year 2012 up until 2512, and is known as the turning point in the history of Humanity and the Supernaturals on Earth.
In 2012 the first portals from Hell opened on Earth without warning, bringing forth legions of Demonic invaders with seemingly no just cause or drive except their thirst for blood. Almost immediately the armies of Heaven arrived to defend Humanity and fight back against their Hellish rivals.
Supernaturals, formerly hidden among the Humans of Earth, revealed themselves to the world and joined the battle on behalf of Humanity. At their helm were the Heroes of Old, perhaps the most famous group of heroes in galactic history.
Over 100 years into the war, the Heroes of Old split in half due to a 'civil war' amongst them. The two brothers Daniel Almis and Ven Almis failed to agree on almost anything, leading to a violent confrontation that nearly killed Ven. Afterwards Dan left the group, taking some of them with him, and leaving the others to continue fighting the war alone.
Formation of the UEG
200 years into the war, Humanity finally stood for themselves. They had advanced their technology in response to the constant attacks on their people and cities, uniting their nations into the United Earth Government. The UEG, the Kingdom of Heaven, and the remaining Heroes of Old now all stood against the armies of Hell together. In the 2300s the UEG developed a new line of soldiers, the best of the best, which they named Elite Commandos. These soldiers became the frontline of the battlefield against the demons.
By 2400 there came a third party in the mystic forces of the war; Purgatory. In his absence Daniel Almis had unlocked the ancient realm and harnessed its powers, directing its endless armies of souls to try and bring a swift end to the war. After many battles the immense power became to much for Dan, forcing the Heroes of Old to step in and defeat him, sealing Purgatory away safely. Dan once again retreated, adamant he could discover an end to the war before his brother.
The Horseman of War
In the year 2512, the Heroes of Old finally discovered what had caused this ongoing conflict. The Second Seal in Heaven's tombs had been broken, meaning the Horseman of War was free. Quickly they summoned the Horseman beneath Heaven, confronting him as a united force. The Heroes of Old, the Elite Commandos of the UEG, and the Angels of Heaven all faced the Horseman in a long, tiring battle, but eventually prevailed and defeated the cruel entity. Upon its defeat the portals of Hell began to close, sealing off the realm and ending the 500 year war.
The 500 Year War left Earth ravished by its battles, yet Humanity had advanced greatly in terms of unity and technology. They were now a star-faring civilisation, ready to expand their horizons into the galaxy, and also accept the presence of their Supernatural neighbours who had protected them throughout the war.