John VIII Palaiologos

John VIII Palaiologos became Roman emperor in 1425, inheriting a Constantinople already squeezed by Ottoman expansion. Born in December 1392, he spent twenty-three years on the throne attempting what his predecessors could not: reuniting the fractured halves of Christianity in hopes that Catholic Europe would send armies to hold the East. The theological summit, the papal negotiations, the promises — all of it bought time but no relief. He died on 31 October 1448, passing the throne to his brother Constantine XI, who would watch the city fall five years later.