In 939, an Obodrite attack left a Saxon army routed and its margravial leader dead. Gero in revenge invited thirty Slav chieftains to a banquet whereat he killed all but one, who managed to escape by accident. In response, the Stodorani revolted against German overlordship and chased the Germans across the Elbe, but Gero was able to reverse this before Otto's arrival in Magdeburg later in the year. He subsequently bribed Tugumir, a baptised Slav prince, to betray his countryman and make his people subject to Germany. Soon after, the Obodrites and the Wilzes made submission.