Between the beginning of the sixth century and the end of the seventh Bohemia had been occupied by a variety of Slav tribes, entering from the East and North. By the time of Charlemagne the Franks began to look on it as a dependency of the Empire, though the degree of Frankish control and level of Frankish interest was still small.

No traces have so far been found in Bohemia of Christian objects or institutions that can be dated before about the middle of the ninth century. In 845 fourteen Bohemian chieftains (duces) came to Regensburg asking for Christian instruction. Thus by the time when an embryonic Bohemian state was coming into existence—in the middle of the ninth century—we can assume some slight influence of Christianity during the preceding fifty years and some stirrings of interest on the Slav side in entering into closer relations with Christendom. The event of 845 must not be taken as a widespread, still less a general conversion of the country. Information is extremely scarce compared with contemporary Moravia and Pannonia. We gain the impression that Bohemia (where Prague appears to be the most active centre throughout the ninth century) was socially and politically less advanced than the Moravian lands. Its development was stimulated by the great Franko–Moravian rivalry. Thus in 858 the Bohemians were already prepared to give Moravia military help against the Franks and closer relations were surely maintained from that time. But only towards the end of the century do the names of Bohemian rulers enter the records.