Today is, in the old calendar, the feast of Cyril and Methodius, slavic brothers who became bishops. As missionaries they were sent to catechize the slavs in the east since they spoke their language. As I was reading their story in Butler's Lives this morning I came across this:
In 863 the two brothers set out with a number of assistants and came to the court of Rostislav (Prince of Moravia); they were well received and at once got to work....The Byzantine missionaries, armed with their pericopes from the Scriptures and liturgical hymns in Slavonic, pursued their way with much success, but were soon handicapped by their lack of a bishop to ordain more priests. The German prelate, the bishop of Passau, would not do it and Cyril therefore determined to seek help elsewhere.