Conversely, in the Eastern Mediterranean territories that ceased being part of the Empire during that period, there emerged almost no competing claim of Imperial legitimacy. In their different ways, the Avars and Slavs in the Balkans, and the Sasanians and Muslims in the Levant and Northern Africa, had different models of governance and no appetite for posing as Romans. This may also be linked to their inability to conquer the Imperial capital despite numerous attempts, as is suggested by the counter-example of the Ottoman Sultans claiming the Imperial title after 1453.