The Antoninos

"The decline of Rome was the natural and inevitable effect of immoderate greatness. Prosperity ripened the principle of decay; the cause of the destruction multiplied with the extent of conquest; and, as soon as time or accident and removed the artificial supports, the stupendous fabric yielded to the pressure of its own weight. The story of the ruin is simple and obvious: and instead of inquiring why the Roman Empire was destroyed we should rather be surprised that it has subsisted for so long".

Edward Gibbon, Decline and Fall of the Roman Empire