Louis the German
According to the "Annals of Fulda", around August 15, 846, Louis the German, King of East Francia (r. 843–876) launched a campaign "against the Moravian Slavs, who were planning to defect". The exact circumstances of his expedition are unclear. For instance, Vlasto writes that the Frankish monarch took advantage of the internal strife which followed Mojmír's death, while according to Kirschbaum, Mojmír was captured and dethroned during the campaign. However, it is without doubt that Louis the German appointed Mojmír's nephew, Rastislav, as the new duke of Moravia during this campaign.