This paper compares the institutional history of the Han Dynasty (206 BC–AD 220), Tang Dynasty (AD 618–AD 906) and the Roman Empire (27 BC–AD 476). I document a common institutional reform in all three cases: the central government assumed power to appoint key regional officials and diffused authority across a greater number of regional officials. I argue that this served to increase coordination costs among key regional officials, making rebellion and resistance to central directives more costly. As a result, this institutional reform shifted the balance of power toward the central government, giving it more control.
