<Tr> <Th> Name </Th> <Th> Duration </Th> <Th> Notes and references </Th> </Tr> <Tr> <Td> Roman Empire </Td> <Td> 4th.--13th c . </Td> <Td> The Eastern Roman / Byzantine Empire was the foremost Christian power in the early medieval period, but under pressure from the Islamic conquests and the Turkic expansion it declined in the high medieval period . It fell to Frankish conquest in 1204 and although restored in the 1260s it did not regain its former stature . </Td> </Tr> <Tr> <Td> Bulgarian Empire </Td> <Td> 10th c . </Td> <Td> </Td> </Tr> <Tr> <Td> Serbian Empire </Td> <Td> 14th c . </Td> <Td> </Td> </Tr>

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