other · 800 · Rome
On Christmas Day 800, in St Peter's, Leo III crowned Charles king of the Franks as emperor of the Romans. Constantinople — where a woman, Irene, held the throne — read it as usurpation. From that morning the church's two halves answered to rival empires, and the road to 1054 ran straighter.
Two empires now claim Rome's name — the political ground of the East–West estrangement.