Sergius III may refer to:
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Pope Sergius III
Pope Sergius III ( − 14 April 911) was the bishop of Rome and nominal ruler of the Papal States from 29 January 904 to his death. He was pope during a period of violence and disorder in central Italy, when warring aristocratic factions soug ...
(reigned 897 and 911), Italian-born pope
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Sergius III of Naples, duke in the 990s
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Sergius III of Amalfi, duke in 1031–1073
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