Caligula, Nero and Family: Rule by the Julio-Claudians from Tiberius to Nero. Includes a brief biography of each emperor.
Crazy Caesars of Rome: Short biographies of the personal lives of insane Roman emperors.
De Imperatoribus Romanis: On-line encyclopedia on the rulers of the empire from Augustus (27 B.C.-14 A.D.) to Constantine XI Palaeologus (1449-1453).
De Imperatoribus Romanis (DIR): Online encyclopedia covering the rulers of the Roman Empire from Augustus (27 BC-AD 14) to Constantine XI Palaeologus (1449-1453).
Imperial Stemmata: Provides detailed family charts for the different imperial dynasties of ancient Rome.
Numerian: Information on the life and death of the Roman Emperor Numerian.
Portraits of Roman Emperors: Color photographs of statues of some Roman Emperors, including Augustus, Constantine and Hadrian.
Roman Emperor: Essay from Wikipedia that lists the history and powers of the office of Roman Emperor.
Roman Emperors in Marble: Includes 16 pictures of Roman Emperors from the Ny Carlsberg Glytotek collection.
Roman Empire In Turmoil 180-285: Overview the imperial reigns of the Severan emperors as part of a bigger work chronicling the Roman empire in turmoil from 180-285 AD.