Methodius and Constantine were successful missionaries in Moravia because they translated the Bible and liturgy into Slavic
Having been called and sent by Emperor Michael to Moravia (which is nowadays the Czech Republic), the brothers Methodius and Constantine reached the country in 863. There, they taught and preach in Slavic, the language of the people, for several years. Their biggest accomplishment in Moravia was to develop a special Slavic alphabet and translate the Bible and liturgy into that language.
