The world, circa 7th century A.D.: the European continent lays dormant and relatively uneventful, while in the East, the lands of Turkey and the Middle East and North Africa, a political storm brews. The Byzantine emperor Maurice is murdered by an assassin plunging the Eastern Roman empire into chaos. Sensing an opening, Persian troops sweep over the area, laying siege to the capital in Constantinople. From the crucible of war emerges Heraclius, who makes key alliances to throw back Persian forces, and then leads the army into Persia proper.

On this day, December 12, in 627, the climactic battle took place between the two empires that controlled most of the known world between them. Byzantine Empire armies met Persian troops at the Battle of Nineveh, modern-day Northern Iraq.

Heraclius feigned a retreat across the Tigris river, drawing out the Persian troops, and then turned back to strike them. The battle was a rout, a total victory for the Byzantine Empire. Heraclius recovered conquered lands and great religious treasures like the True Cross, a remnant of the one which Jesus Christ was crucified on, thought lost with the Persian sack of Jerusalem. But his victory proved Pyrrhic, as the great Arab armies came out of Africa to sweep over the lands the Byzantines were too exhausted to defend.