In 862, the brothers began the work which would give them their historical importance. That year Prince Rastislav of Great Moravia requested that Emperor Michael III and the Patriarch Photius send missionaries to evangelize his Slavic subjects. His motives in doing so were probably more political than religious. Rastislav had become king with the support of the Frankish ruler Louis the German, but subsequently sought to assert his independence from the Franks. It is a common misconception that Cyril and Methodius were the first to bring Christianity to Moravia, but the letter from Rastislav to Michael III states clearly that Rastislav's people "had already rejected paganism and adhere to the Christian law." Rastislav is said to have expelled missionaries of the Roman Church and instead turned to Constantinople for ecclesiastical assistance and, presumably, a degree of political support. The Emperor quickly chose to send Cyril, accompanied by his brother Methodius. The request provided a convenient opportunity to expand Byzantine influence. Their first work seems to have been the training of assistants. In 863, they began the task of translating the Gospels and necessary liturgical books into the language now known as Old Church Slavonic and traveled to Great Moravia to promote it. They enjoyed considerable success in this endeavour. However, they came into conflict with German ecclesiastics who opposed their efforts to create a specifically Slavic liturgy.