Mediolanum had fallen. Belisarius wrote a furious letter to Justinian explaining what happened, and the emperor immediately recalled Narses and reaffirmed Belisarius's leadership. His army tore through the Ostrogothic territory and soon laid siege to Ravenna, which they brought to the brink of surrender. But the Ostrogothic King Vitiges had written to the Persian Empire urging them to take advantage of Rome's distraction. Sure enough, Justinian found himself faced with a Persian army in the East, and he sent orders to Belisarius to leave Ravenna and return to defend Constantinople. Belisarius hated seeing his victory snatched from him, however, and almost refused to do it. Hearing of his displeasure, the Ostrogoths reached out to him and offered to make him their new king - no surrender necessary. Belisarius accepted their proposal, then immediately turned on them and declared the city for Justinian. Still, his greed cost the empire time. Justinian was furious that Belisarius had disobeyed his orders to return and wasted precious months solidifying control over the Ostrogoths while Persia threatened to overrun the heart of the empire. He could no longer trust his most valued general.