After the Treaty of Verdun (843), Frankfurt became to all intents and purposes the capital of East Francia and was named "Principalis sedes regni orientalis" (principal seat of the eastern realm). Kings and emperors frequently stayed in Frankfurt, and Imperial Diets and church councils were repeatedly held there. The establishment of religious monasteries and numerous endowments to the local church furthered the urban community. Also, as the Holy Roman Emperor had no permanent residence anymore, Frankfurt remained the center of imperial power and the principal city of Eastern Francia.