An extensive empire must be supported by a refined system of policy and oppression; in the centre, an absolute power, prompt in action and rich in resources; a swift and easy communication with the extreme parts; fortifications to check the first effort of rebellion; a regular administration to protect and punish; and a well-disciplined army to inspire fear, without provoking discontent and despair.
Edward Gibbon (2008). “The History of the Decline and Fall of the Roman Empire”, p.302, Cosimo, Inc.