Rastislav or Rostislav, also known as St. Rastislav, (Latin: Rastiz, Greek: Ῥασισθλάβος / Rhasisthlábos) was the second known ruler of Moravia (846–870). Although he started his reign as vassal to Louis the German, king of East Francia, he consolidated his rule to the extent that after 855 he was able to repel a series of Frankish attacks. Upon his initiative, brothers Cyril and Methodius, sent by the Byzantine Emperor Michael III in 863, translated the most important Christian liturgical books into Slavonic. Rastislav was dethroned by his nephew Svatopluk I of Moravia, who handed him over to the Franks. He was canonized by the Eastern Orthodox Church in 1994. Early life According to the Annals of Fulda, Rastislav was a nephew of Mojmir I, the first known ruler of Moravia. His career before 846 is unknown, but it is conceivable that he served as a hostage for his uncle at Louis the German's court. The latter invaded Moravia in 846, deprived Mojmir I of his throne, and installed Rastislav as the new duke of Moravia. Rastislav seems to have already been Christian when he became duke, but there is no doubt that he was baptized at the latest in 846 as part of the conditions for his support by the East Frankish king. Towards independence In the first eight years of Rastislav's reign there is no report of Moravian rebellion, which suggests that he remained loyal to Louis the German. In this period Rastislav seems to have acquired new territories in the east and established a border with the First Bulgarian Empire. According to the Annals of St-Bertin, in 853 Charles the Bald, king of West Francia, bribed the Bulgarians to ally with the Slavs (apparently the Moravians) and together attack Louis the German's kingdom. In the course of the Bulgarian–Moravian attack, Louis the German deposed his prefect of the Eastland, Radbod, who soon allied with Rastislav. The alliance suggests that, by this time, Rastislav felt secure enough to challenge Frankish overlordship. In 855 the East Frankish king gathered a large army to invade Moravia. His army, however, foundered before the walls of one of Rastislav's strongholds, perhaps at Mikulčice (now in the Czech Republic) that seems to have been rebuilt in the previous years. Unprepared for a prolonged siege, the king was forced to withdraw from the region. As the king was retreating, his army defeated a large Moravian