The Battle of Ravenna is fought between the troops of Byzantine Emperor Leo III the Isaurian, and a force of Italians, raised by Pope Gregory II in defense of image worship, which Leo had outlawed. After a severe struggle, the Greeks are routed; thousands are killed in flight to their ships. The waters of the Po River are so infected with blood, it is said, that for six years the inhabitants of Ravenna will not eat fish from the river.
