influence both inside and outside the imperial frontiers as never before. As George Ostrogorsky points out: "The Patriarchate of Constantinople remained the center of the Orthodox world, with subordinate metropolitan sees and archbishoprics in the territory of Asia Minor and the Balkans, now lost to Byzantium, as well as in Caucasus, Russia and Lithuania. The Church remained the most stable element in the Byzantine Empire." In terms of religion, Byzantine Greek Macedonia is also significant as being the home of Saints Cyril and Methodius, two Greek brothers from Thessaloniki (Salonika) who were sent on state-sponsored missions to proselytize among the Slavs of the Balkans and east-central Europe. This involved Cyril and Methodius having to translate the Christian Bible into the Slavs' own language, for which they invented an alphabet that became known as Old Church Slavonic. In the process, this cemented the Greek brothers' status as the pioneers of Slavic literature and those who first introduced Byzantine civilization and Orthodox Christianity to the hitherto illiterate and pagan Slavs. Identity Self-perception In modern Byzantine scholarship, there are currently three main schools of thought on medieval eastern Roman identity. First, a school of thought that developed largely under the influence of modern Greek nationalism, treats Roman identity as the medieval form of a perennial Greek national identity. In this view, as heirs to the ancient Greeks and of the Roman state, the Byzantines thought of themselves as Rhomaioi, or Romans, though they knew that they were ethnically Greeks. Second, which could be regarded as preponderant in the field considers "Romanity" the mode of self-identification of the subjects of a multi-ethnic empire at least up to the 12th century, where the average subject identified as Roman. Third, a line of thought argues that the eastern Roman identity was a separate pre-modern national identity. The established consensus in the field of Byzantine studies does not call into question the self-identification of the "Byzantines" as Romans. The defining traits of being considered one of the Rhomaioi were being an Eastern Orthodox Christian and more importantly speaking Greek, characteristics which had to be acquired by birth if one was not to be considered an allogenes or even a barbarian. The term mostly used to describe someone who was a foreigner to both the Byzantines and their state was ethnikós (Greek: ), a term which originally described non-Jews or non-Christians, but had lost its religious meaning. In