Rastislav was a ninth-century ruler of Great Moravia who reigned from 846 to 870. Initially a vassal to the East Frankish king Louis the German, he eventually worked to strengthen his independence and resist Frankish influence. He is most notably remembered for requesting missionaries from Constantinople to provide religious instruction in the native Slavic language. This request led to the arrival of the brothers Cyril and Methodius, who translated liturgical texts into Slavonic. After being deposed by his nephew, Svatopluk I, he was eventually handed over to the Franks and died in Regensburg.