In many ways the early third century BC was the climax of ancient Greek history. For a brief period Macedonian power and Greek culture reigned supreme in the Near and Middle East. New Greek cities were founded at strategic points throughout this enormous region. A person could travel from Egypt to the borders of India speaking only Greek. The heyday of the Hellenistic kingdoms, however, was brief. Internal and external threats called their survival itself into question within a generation of their foundation.
The Seleucids' kingdom proved the most vulnerable. From their capital at Antioch the Seleucids struggled with limited success to maintain control of the Asian territories of Alexander's empire. Already before the end of the fourth century BC Seleucus I ( 311-281) had ceded his dynasty's claims to Alexander's conquests in India to Chandra Gupta (ca. 324-300), who had conquered northern India and founded the Maurya dynasty. Further territorial losses followed in the third century BC. While Seleucus' successors fought bitterly among themselves over the succession to the throne, enemies attacked their western and eastern frontiers. In the west, the Attalids of Pergamum seized control of much of Anatolia; in the east, the Parthians (Iranian-speaking nomads) and rebellious Greek settlers carved out kingdoms for themselves in eastern Iran and Bactria.
The Ptolemies were more secure in their Egyptian fortress than their Seleucid rivals. For over a century and a half no enemy succeeded in breaching Egypt's defenses. Nevertheless, Ptolemaic authority in Egypt also weakened significantly in the third century BC. Native rule was reestablished in southern Egypt in the last decades of the century, while succession crises sapped the dynasty's strength. By 200 BC, the Ptolemies ruled only Lower and Middle Egypt. With total collapse of the Hellenistic state system virtually in sight, Antiochus III ( 223-187 BC) and Ptolemy V ( 204-180 BC) launched vigorous counteroffensives that seemingly restored their dynasties' authority over most of their former territory. Before the Seleucids and Ptolemies could fully consolidate their hold on their kingdoms, however, disaster struck in the form of the Romans. Roman expansion into the eastern Mediterranean was so dramatic and unexpected that the historian Polybius could justifiably begin his great history with the deceptively simple ques-