Rastislav of Moravia

Rastislav
Rastislav on a modern icon as an Orthodox saint.
Duke of Moravia
Reign	846–870
Predecessor	Mojmir I
Successor	Svatopluk I
Died	870
House	House of Mojmír
Father	Boso-Hosdius (?)

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 two brothers, Cyril and Methodius sent by the Byzantine Emperor Michael III in 863, translated the most important Christian liturgical books into Slavonic in his realm. Rastislav was dethroned by his nephew Svatopluk I who handed him over to the Franks.

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.

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, Ratpot who soon formed a rebel alliance with Rastislav. This alliance suggests that by that time Rastislav felt secure enough to challenge Frankish overlordship.