Battle of Heracl by Piero della Francesca
Fresco painting 1458-1466 . In 615 the Emperor Persian Sassanid Khosrau II conquered Jerusalem , also possession of the relic of the True Cross . With this he does in a blasphemous worship as a living god. The Byzantine emperor Heraclius then challenge him in battle ( 628 ), winning it and, later, killing him by decapitation .