In 862 C.E., Rostislav, prince of Moravia (modern - day eastern Czechia, western Slovakia, and western Hungary), sent to Byzantine Emperor Michael III the request appearing in the opening paragraph ​ — that he send teachers of the Scriptures.
पण, आपल्या देशांवरील जर्मन जमातींच्या राजकीय आणि धार्मिक प्रभावाची चिंता रास्तीस्लाव्हला भेडसावत होती.