The Byzantine empire remains the dominant political and cultural power in the Balkans during these early medieval centuries. Major urban centers include Constantinople, the empire’s political and religious capital, and Thessaloniki, strategically situated along the major land route connecting Byzantium with the West. Among the most important events in church history are the Iconoclastic controversy (726–843) and the spread of the Orthodox Christian faith beyond the empire’s borders. The development of a large, domed, centrally planned building type is among the great advances in Byzantine architecture of the period. In the arts, silk weaving and cloisonné enameling emerge as new techniques for which Byzantine craftsmen became famous throughout the medieval world.