Cassius Dio (/ˈkæʃəs ˈdiːoʊ/; fl. 291–297) was a Roman senator who was appointed consul in AD 291.
Cassius Dio was either the grandson or great-grandson of his namesake, the historian Cassius Dio, whose family originated in Bithynia. He was appointed consul posterior in 291 alongside Gaius Junius Tiberianus at quite a young age. This was followed by a posting as Proconsular governor of Africa from approximately 1 July 294 to 1 July 295. Then on 18 February 296, he was appointed Praefectus urbi of Rome, a position he held until 297.
Cassius Dio owned a house on the Palatine Hill called the Domus Dionis. At some stage, he and 12 other senators each contributed 400,000 sesterces, probably for the construction of a building.
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