Pax Romana

It was during this period that the Roman Empire achieved its greatest territorial extent under Trajan in 117. Additionally, the Roman Empire's population is estimated to have peaked at 70 million people during the Pax Romana, accounting for 33% of the world's population. Following the Pax Romana, and according to Cassius Dio, the tyrannical reign of Commodus, later followed by the Year of the Five Emperors and the Crisis of the Third Century, marked Rome's descent "from a kingdom of gold to one of iron and rust".

Overview

The Pax Romana, spanning from 27 BC to AD 180, stands as one of the longest enduring periods of peace in history. However, Walter Goffart wrote: "The volume of the Cambridge Ancient History for the years AD 70–192 is called 'The Imperial Peace', but peace is not what one finds in its pages". On the other hand, Arthur M. Eckstein writes that the period must be viewed in contrast to the much more frequent warfare in the 3rd and 4th centuries BC under the Roman Republic.

Eckstein also notes that the initial Pax Romana appeared during the Republic, and that its temporal span varied upon geographical region as well: "Although the standard textbook dates for the Pax Romana, the famous 'Roman Peace' in the Mediterranean, are 31 BC to AD 250, the fact is that the Roman Peace was emerging in large regions of the Mediterranean at a much earlier date: Sicily after 210 [BC], the Italian Peninsula after 200 [BC]; the Po Valley after 190 [BC]; most of the Iberian Peninsula after 133 [BC]; North Africa after 100 [BC]; and for ever longer stretches of time in the Greek East." Thomas F. Madden explained the dating of 27 BC as avoiding the civil wars of the 1st century BC. The true origins of Pax Romana for him are in the 2nd century BC, after Rome had eliminated all of its serious military rivals and brought an unprecedented peace and prosperity to the lands of their empire. Tim Cornell argued that Pax Romana in the sense of the absence of major inter-state wars began in the Second century BC. Over the course of the last two centuries of the Republic, the character and frequency of these wars declined. Almost continuous warfare in the Fourth and Third centuries BC became sporadic and punctuated by long periods of peace.

The first known record of the term Pax Romana appears in a writing by Seneca the Younger in AD 55. The concept was highly influential, and the subject of theories and attempts to copy it in subsequent ages. Arnaldo Momigliano noted that "Pax Romana is a simple formula for propaganda, but a difficult subject for research."

For most historians, the Pax Romana began when Octavian (Augustus) defeated Mark Antony and Cleopatra in the Battle of Actium on 2 September 31 BC and became Roman emperor. He became princeps, or first citizen. Lacking a good precedent of successful one-man rule, Augustus created a junta of the greatest military magnates and stood as the front man. By binding together these leading magnates in a coalition, he eliminated the prospect of civil war. The Pax Romana was not immediate, despite the end of the civil wars, because fighting continued in Hispania and in the Alps. Nevertheless, Augustus closed the Gates of Janus (a ceremony indicating that Rome was at peace) three times, first in 29 BC and again in 25 BC. The third closure is undocumented, but Inez Scott Ryberg (1949) and Gaius Stern (2006) have persuasively dated the third closure to 13 BC with the commissioning of the Ara Pacis. At the time of the Ludi Saeculares in 17 BC the Concept of Peace was publicized, and in 13 BC was proclaimed when Augustus and Agrippa jointly returned from pacifying Hispania and the Alps. The order to construct the Ara Pacis was probably part of this announcement.

Romans regarded peace not as an absence of war, but as a rare situation which existed when all opponents had been beaten down and lost the ability to resist. Augustus' challenge was to persuade Romans that the prosperity they could achieve in the absence of warfare was better for the Empire than the potential wealth and honor acquired when fighting a risky war. Augustus succeeded by means of skillful propaganda. Subsequent emperors followed his lead, sometimes producing lavish ceremonies to close the Gates of Janus, issuing coins with Pax on the reverse, and patronizing literature extolling the benefits of the Pax Romana.

After Augustus' death in AD 14, most of his successors as Roman emperors continued his politics. The last five emperors of the Pax Romana are known as the "Five Good Emperors".