Use of the Greek language was already widespread in the eastern parts of the Roman empire when Constantine moved its capital to Constantinople, although Latin was the language of the imperial administration. From the reign of Emperor Heraclius (), Greek was the predominant language amongst the populace and also replaced Latin in administration. At first, the Byzantine Empire had a multi-ethnic character, but following the loss of the non-Greek speaking provinces with the 7th century Muslim conquests it came to be dominated by the Byzantine Greeks, who inhabited the heartland of the later empire: modern Cyprus, Greece, Turkey, and Sicily, and portions of southern Bulgaria, Crimea, and Albania. Over time, the relationship between them and the West, particularly with Latin Europe, deteriorated.