Doson in 229 did not resolve the conflict between the allied koina and Macedon, and the threat posed by Illyrian piracy to seaborne traffic in the Adriatic was in no way diminished. The Aitolians supported the revolt of Thessaly from Macedonian control, provoking a vigorous response from Doson that stripped them not only of their hopes of controlling Thessaly but also of eastern Phokis.109 The Boiotians also lost Opountian Lokris.110
Phokis appears to have regained its political independence as a koinon and now made an alliance with the Boiotians. The first lines of the inscription recording the Boiotian-Phokian alliance (T28), which may have delineated obligations for defensive or offensive cooperation, are missing, but what survives is striking for its provision of safekeeping of goods in the other’s territory, presumably in the event of a hostile invasion (ll. 1–6). Each koinon preserved its own officials, elections, and oaths; Phokis clearly preserved its independence from Boiotia, while both states essentially committed to preserving each other’s autonomy in the tumultuous atmosphere of the early 220s. This alliance was strengthened by the inclusion of the Achaians not much later (T42). The Achaian polity continued to grow: Aigina, Hermione, and most of Arkadia, according to Plutarch, now joined the koinon.111 After years of Achaian attempts, Argos finally joined and was followed by neighboring Phleious.112
In the spring of 228, the Aitolians and Achaians received embassies from unaccustomed visitors: the Romans sought to “explain the causes of the war and their crossing [to Illyria], and then gave an account of what they had done.”113 Both ethnē, according to Polybios, received the ambassadors with philanthrōpia. The episode provides our first evidence for direct contact between the Romans and the Aitolian and Achaian koina, at this time the most powerful states in mainland Greece. It is likely that the embassy was motivated in part by an awareness of the Aitolian-Achaian involvement in the Illyrian War, which preceded the Roman arrival, but it also reveals a cautious approach: the Romans were aware that they needed to explain their presence in an area where they had previously had no established interests.
The resolution of the Illyrian conflict was well timed for the Achaians, for it freed them to focus on the new threat posed by Kleomenes III in Sparta. Sometime in 229, the Spartans seized the eastern Arkadian cities of Tegea, Mantineia, Orchomenos, and Kaphyai. These cities had joined the Achaian koinon in 235 but had then switched allegiance to become members of the Aitolian koinon perhaps around 233. According to Polybios, the Aitolians approved Kleomenes’ seizure of these cities as a means of weakening Achaian power, but the claim is highly dubitable.114 When Kleomenes attacked a fortification in the territory of Megalopolis, a prized part of Achaia since 235, the Achaians declared war.115 The struggle focused initially around control of Arkadia, where the Achaians had limited success until spring 227.116 Despite a serious setback in open battle against Spartan forces at Mount Lykaion, the Achaians managed to regain Mantineia, lay siege to Orchomenos, and protect Megalopolis against Spartan incursions, while Kleomenes dealt ruthlessly with ongoing challenges to his political authority at home and dramatically increased Spartan military strength.117 Kleomenes put relentless pressure on Arkadia, and particularly Megalopolis, while political tensions were straining the hastily stitched seams of the Achaian koinon, which had expanded so rapidly in the previous decade and a half. In response to these pressures, Aratos took a step in winter 227/6 that had previously been unthinkable: he approached the reigning Macedonian king, Antigonos Doson, seeking his military support if the pressing need should arise. But political pressure made it impossible for him to do this directly, so he persuaded several family friends in Megalopolis, including the Cynic philosopher Kerkidas, to approach the Achaians and, citing the hardships being endured by the city, seek their permission to send an embassy to Antigonos.118 Polybios claims that Aratos and the Achaians as a whole were motivated by the pressures of the war against Kleomenes and by fear of Aitolian territorial depredations in the Peloponnese.119 It is difficult to determine how objective this claim is, for we have no independent evidence of Aitolian activity in the area in this period or of a rupture in the Achaian-Aitolian alliance concluded upon the accession of Demetrios in 239. In any case, the embassy was warmly received by Antigonos, who offered his help as soon as the Achaians should formally request it; Aratos nevertheless encouraged the Achaians to resolve the war on their own.120
In the summer and autumn of 226, however, the Achaians suffered three major setbacks that together made independent success in the war seem unlikely: Ptolemy withdrew the subsidies his kingdom had been providing since 251/0, choosing instead to fund the Spartans as being more likely than the Achaians, now, to oppose Antigonos; Kleomenes regained control of Mantineia, expelling the Achaians’ mercenary garrison and slaughtering the entire population of Achaian settlers in the town; and finally, Kleomenes inflicted a heavy defeat on the full Achaian military levy at a site called Hekatombaion in western Achaia, in the territory of Dyme, thus moving the conflict out of Arkadia and into the heart of Achaian territory.121 The Achaians spent the first half of 225 in negotiations, first with Kleomenes and then with Antigonos. Tension within the koinon was palpable. A pro-Spartan faction encouraged treating with Kleomenes, while other groups in Achaia were bitterly opposed to the pursuit of Macedonian support, and socioeconomic unrest was widespread.122 In this atmosphere of factionalism, Aratos was either unable or unwilling to engage the Achaians in an open debate about inviting Doson to assist them; instead he is reported to have used covert methods to ensure a breakdown of the renewed negotiations between the Achaians and Kleomenes.123 So it is not surprising that Kleomenes made so much headway in detaching member poleis from the koinon: in the summer and autumn of 225, he took control of Pellene, Pheneos, and Kaphyai, which sundered the territory of the koinon in two, and then worked systematically to seize the entire eastern portion of it, including Kleonai, Argos, Epidauros, Hermione, and Troizen.124 Meanwhile the Achaians, under increasing pressure, consented to an alliance with Antigonos, but his demand for Acrocorinth, the old Macedonian garrison that Aratos had fought for years to take, was a sticking point. When, however, the citizens of Corinth ordered Aratos out of their city and invited Kleomenes in, the Achaians, further pressed by Kleomenes’ three-month siege of Sikyon, felt justified in granting Antigonos what he wanted, thereby reversing the anti-Macedonian stance that had guided Achaian policy for more than twenty-five years.125
In the spring of 224, Antigonos arrived in the Megarid with a large force, but these were prevented from entering the Peloponnese by Kleomenes, who set up a strong line of defense across the isthmos and around Corinth, which Antigonos initially found impossible to break.126 Megara, the most northerly of all the members of the Achaian koinon, was thus cut off from the larger regional state, and Antigonos transferred it to the Boiotian koinon, apparently after securing the consent of the Achaians.127 The war against Kleomenes took a sudden and unexpected turn when the Argives decided to revolt from Kleomenes with an appeal to the Achaians and Antigonos, who immediately rallied to their aid. With hostile forces at his back, Kleomenes was forced to abandon Corinth and retreat to Sparta, while some other cities apparently returned to the Achaian koinon.128
The revolt of Argos from Kleomenes was a turning point in the war. At the Achaians’ regular autumn council meeting in 224, according to Polybios, Antigonos was made hēgemōn of all the allies.129 This is in all probability an allusion to the so-called Hellenic Alliance. All our evidence for the nature of this alliance comes from Polybios’s narrative of the Social War (220–217), but it can be retrojected with some confidence to the Kleomenean War. In addition to the Macedonians and the Achaians, the members of this alliance were the other koina of mainland Greece that were already on good terms with the two principal members: the Epeirotes, Phokians, Boiotians, Akarnanians, and Thessalians.130 It was, in other words, an alliance of koina. It is impossible to know who was responsible for developing this idea; one immediate inspiration may have been the realization, implicit in the consensual transfer of Megara from the Achaian to the Boiotian koinon, that interstate cooperation might be achieved on a very large scale indeed by a partnership of the several koina of mainland Greece. The organization is sometimes compared to the League of Corinth developed by Philip II and to the Hellenic Alliance organized
