The mission of Constantine and Methodius had great success among Slavs in part because they used the people's native language rather than Latin or Greek. In Great Moravia, Constantine and Methodius also encountered missionaries from East Francia, representing the western or Latin branch of the Church, and more particularly representing the Carolingian Empire as founded by Charlemagne, and committed to linguistic, and cultural uniformity. They insisted on the use of the Latin liturgy, and they regarded Moravia and the Slavic peoples as part of their rightful mission field.