On the eve of the Second Punic War in 218 BC the Roman Republic was essentially an Italian power, controlling the peninsula south of the Po valley and the islands of Sicily, Sardinia and Corsica. In just thirty years Rome then defeated the only other powers in the Mediterranean world that could possible challenge her: Carthage (Second Punic War 218-201), Antigonid Macedon (Second Macedonian War 200-196) and the vast Seleucid Empire (War with Antiochus 192-188). While Rome still directly controlled very little territory outside Italy and the islands as provinces – the Senate preferred an hegemonic approach – the empire was completely established by 188 in the sense that there was no one left who could even remotely threaten Rome. Turning clients into provinces would occupy the next couple of centuries. Just how powerful Rome was by 188 is illustrated by a single incident, one that did not in fact involve any show of force.
After the death of Alexander III (the Great) in 323 his empire collapsed as his lieutenants fought over the spoils for the next for the next half century. This was the Age of the Successors, and the virtually endless war of the period produced the three major powers of the Hellenistic world, all of them Greco-Macedonian monarchies defended by almost exclusively Greco-Macedonian armies. The descendants of Antigonus the One-Eyed managed to capture the Macedonian homeland, replacing the now defunct Temenid dynasty of Alexander with the Antigonid dynasty. Another young officer, Ptolemy son of Lagos, seized Egypt and established the Ptolemaic or Lagid dynasty, the last member of which was the famous Cleopatra VII. The Asian territory, stretching from the Mediterranean to India, fell to Seleucus, after whom the Seleucid dynasty would be named.
For most of the third century these three states existed in a precarious balance of power, two periodically joining against the third when it seemed to be growing too strong. Consequently, while there was constant scheming and wars of expansion, the three monarchies continued to exist into the second century. By the end of the third century, however, Egypt had become a weakling under a series of poor kings and was the priority target of the Seleucids. Actually, Egypt had always been a target of the Seleucids, and in the course of the third century the two powers had fought five wars over control of Syria-Palestine, a critical strategic area for both states.
The day of reckoning was delayed by Roman involvement in the east, which led to the defeat of Antiochus III (the Great) in 188 and the loss Asia Minor, his most valuable territory. He died in 187 and was succeeded by his son Seleucus IV Philopator, who was assassinated in 178 and followed by his brother Antiochus IV Epiphanes of biblical fame. In 170 Eulaeus and Lenaeus, ministers of the underage Ptolemy VI Philometor, prepared for an invasion of Palestine, now under Seleucid control, but were thwarted by Antiochus, who in 169 captured Memphis and Ptolemy himself and had himself proclaimed king of Egypt. But the population of Alexandria named Ptolemy’s brother king as Ptolemy VII and fortified the city so well that Antiochus retired from Egypt, leaving Ptolemy VI to duke it out with his sibling. The hoped for fratricidal war of attrition did not occur, however, and the brothers reconciled, leading Antiochus to invade once again in 168. He easily reached Alexandria and began preparing a siege, when a Roman embassy showed up.
Antiochus was well aware of Roman strength and had followed his father and brother in going out of his way to maintain friendly relations with the Republic. He knew the Romans were disinclined to see the Seleucid empire expand, but at this time Rome was involved in the Third Macedonian War (171-168) against Perseus, destined to be the last king of Macedon. There was no doubt of the outcome, but Antiochus presumably believed that Egypt was outside the Roman strategic horizon and that his excellent relations with the Republic would lead them to accept a fait accompli.
The Roman embassy, led by the former consul C. Popillius Laenas, met Antiochus at his headquarters outside Alexandria. Popillius handed the king a letter from the Senate, a note that said something to the effect that the Senate and the Roman People felt it was in the best interests of everyone for Antiochus to return to Asia and leave the Ptolemaic monarchy intact. The king asked for time to consider the “request.” Popillius responded by using his walking stick to draw in the sand a circle around Antiochus and asked him to give his response before he left the circle. Antiochus, ruler of more territory than Rome, at the head of a victorious army and about to achieve what his family had dreamed of for a century, gathered his forces and marched back to Syria. So powerful had Rome become.