Religious Beliefs. Christianity was brought to the area of the Czech Republic during the ninth century by missionaries from Germany to the west (the Latin rite) and the Byzantine Empire to the southeast (the Eastern rite). The missionaries of the Eastern rite were the brothers Constantine (later renamed Cyril) and Methodius, natives of Thessalonica in Macedonia. They arrived in 863, invited by Rostislav (or Rastislav), ruler of the Great Moravian Empire, and devised the first Slavic writing system, in which they published parts of the Bible in a Slavic language that was intelligible to the local population. The arrival of the Magyars in the middle Danube area near the end of the ninth century and their subsequent raids to the north led to the disintegration of the Great Moravian Empire and weakened the influence of the Eastern rite.