This study evaluates the military history and practice of the Roman Empire in the context of contemporary counterinsurgency theory. It purports that the majority of Rome’s security challenges fulfill the criteria of insurgency, and that Rome’s responses demonstrate counterinsurgency proficiency. These assertions are proven by means of an extensive investigation of the grand strategic, military, and cultural aspects of the Roman state. Fourteen instances of likely insurgency are identified and examined, permitting the application of broad theoretical precepts to episodes spanning 300 years of Roman power. In summary, Rome demonstrates remarkable counterinsurgent sophistication, suggesting far more savvy and doctrinal agility than is afforded the Roman Empire by most modern observers.