There are two theories about the shape of this dome: a Byzantine-style dome on spherical pendentives with a ring of windows similar to domes of the later Justinian era, or an octagonal cloister vault following Roman trends and like the vaulting over the s
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The defeat at Brindisi put an end to the restored Byzantine reign in Italy; in 1158 the Byzantine army left Italy and never returned again.
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By the beginning of the 10th century, two powers had come to dominate the Balkans: the Byzantine Empire controlled the south of the peninsula and the coasts, and the Bulgarian Empire held the central and northern Balkans.
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