Rome expanded eastward during the same period, eventually conquering all of Greece, the heartland of the culture the Romans so admired and emulated. While Hannibal was busy rampaging around Italy, the Macedonian King Philip V allied with Carthage against Rome, a reasonable decision at the time because it seemed likely that Rome was going to lose the war. In 201 BCE, after the defeat of the Carthaginians, Rome sent an army against Philip to defend the independence of Greece and to exact revenge. There, Philip and the king of the Seleucid empire (named Antiochus III) had agreed to divide up the eastern Mediterranean, assuming they could defeat and control all of the Greek poleis. An expansionist faction in the Roman senate successfully convinced the Centuriate Assembly to declare war. The Roman legions defeated the Macedonian forces without much trouble in 196 BCE and then, perhaps surprisingly, they left, having accomplished their stated goal of defending Greek independence. Rome continued to fight the Seleucids for several more years, however, finally reducing the Seleucid king Antiochus III to a puppet of Rome.
Despite having no apparent interest in establishing direct control in Greece, the Romans found that rival Greek poleis clamored for Roman help in their conflicts, and Roman influence in the region grew. Despite Rome’s long standing admiration for Greek culture, the political and military developments of this period, from 196 - 168 BCE, helped confirm the Roman belief that the Greeks were artistic and philosophical geniuses but, at least in their present iteration, were also conniving, treacherous, and lousy at political organization. There was also a growing conservative faction in Rome led by Cato the Elder that deliberately and emphatically emphasized Roman moral virtue over Greek weakness.
Philip V’s son Perseus took the throne of Macedon in 179 BCE and, while not directly threatening Roman power, managed to spark suspicion among the Roman elite simply by reasserting Macedonian sovereignty in the region. In 172 BCE Rome sent an army, and Macedon was defeated in 168 BCE. Rome split Macedon into puppet republics, plundered Macedon’s allies, and lorded over the remaining Greek poleis. Revolts in 150 and 146 against Roman power served as the final pretext for the Roman subjugation of Greece. This time, the Romans enacted harsh penalties for disloyalty among the Greek cities, utterly destroying the rich city of Corinth and butchering or enslaving tens of thousands of Greeks for siding against Rome. The plunder from Corinth specifically also sparked great interest in Greek art among elite Romans, boosting the development of Greco-Roman artistic traditions back in Italy.
Thus, after centuries of warfare, by 140 BCE the Romans controlled almost the entire Mediterranean world, from Spain to Anatolia. They had not yet conquered the remaining Hellenistic kingdoms, namely those of the Seleucids in Mesopotamia and the Ptolemies in Egypt, but they controlled a vast territory nonetheless. Even the Ptolemies, the most genuinely independent power in the region, acknowledged that Rome held all the real power in international affairs.
The last great Hellenistic attempt to push back Roman control was in the early first century BCE, with the rise of a Greek king, Mithridates VI, from Pontus, a small kingdom on the southern shore of the Black Sea. Mithridates led a large anti-Roman coalition of Hellenistic peoples first in Anatolia and then in Greece itself starting in 88 BCE. Mithridates was seen by his followers as a great liberator, given the degree of corruption among many Roman officials (one Roman governor had molten gold poured down his throat to symbolize the just punishment of Roman greed). Mithridates fought a total of three wars against Rome, but despite his tenacity he was finally defeated and killed in 63 BCE.
Under the leadership of a general and politician, Pompey (“the Great”), both Mithridates and the remaining independent formerly Seleucid territories were defeated and incorporated either as provinces or puppet states under the control of the Republic. With that, almost the entire Mediterranean region was under Rome’s sway - Egypt alone remained independent.