emperor, [229];
wars of, [231];
murdered by Zimisces, [232]
Nicholas V., pope, sends aid to Constantine XI., [344]
Nicomedia, taken by the Ottomans, [323]
Nineveh, battle of, [138]
Normans, conquer Byzantine Italy, [247];
invade the empire, [259];
second invasion of repelled, [267];
third invasion of, [273]