But Rhodolph was at Vienna before him, where he was joined by others of his allies, who were to meet him at that rendezvous.

Vienna, the capital, was a fortress of great strength.

Upon this frontier post Charlemagne had established a strong body of troops under a commander who was called a margrave; and for some centuries this city, commanding the Danube, had been deemed one of the strongest defenses of the empire against Mohammedan invasion.

Vienna, unable to resist, capitulated.

The army of Ottocar had been so driven in their long and difficult march, that, exhausted and perishing for want of provisions, they began to mutiny.