The Decline and Fall of the Roman Empire · ¶359

If we compute the number and duration of the reigns, it will be found, that a period of six hundred years is filled by sixty emperors, including in the Augustan list some female sovereigns; and deducting some usurpers who were never acknowledged in the capital, and some princes who did not live to possess their inheritance. The average proportion will allow ten years for each emperor, far below the chronological rule of Sir Isaac Newton, who, from the experience of more recent and regular monarchies, has defined about eighteen or twenty years as the term of an ordinary reign. The Byzantine empire was most tranquil and prosperous when it could acquiesce in hereditary succession; five dynasties, the Heraclian, Isaurian, Amorian, Basilian, and Comnenian families, enjoyed and transmitted the royal patrimony during their respective series of five, four, three, six, and four generations;…

Edward Gibbon · Project Gutenberg #734 (Milman edition) — public domain
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