Creating a Common Polity. Emily Mackil
Plataia; it is well known, so a brief recounting will be sufficient here.
In early 431 a force of more than three hundred Thebans, led by their own boiotarchs, attacked Plataia by night, hoping to force the city out of its alliance with Athens and back into the Boiotian koinon that had started to take shape after 446.78 When precisely the Plataians had left the koinon is unknown, but it is likely that the rupture occurred as tensions increased between Athens, with which Plataia was allied, and Sparta, with which most of the rest of Boiotia was. The Thebans certainly saw that a pro-Athenian Plataia increased Boiotia’s vulnerability, and they were encouraged in the attack by some Plataians who wished to make the city over to the Thebans “for the sake of personal power,” a phrase probably alluding to a desire to gain official positions within the koinon.79 The attack was a Theban initiative, not an act of the Boiotian koinon; the other member poleis were either not privy or were uninvolved. Nevertheless it is clear that the Thebans were attempting not to subordinate Plataia to themselves but to make it part of “the Boiotians” (much as they had done in 519): the pro-Theban partisans in Plataia urged the Theban soldiers, once they had entered the city, to go immediately to the houses of their enemies (presumably to slaughter them), but the Thebans were unwilling. They preferred “to make friendly announcements and rather to lead the polis to an agreement and friendship.” The herald accordingly announced that anyone who wished “to make an alliance in accordance with the ancestral customs [ta patria] of all the Boiotians” should lay down his arms.80 The Plataians firmly resisted and managed to take 180 Theban prisoners, while the rest escaped; the prisoners were executed, according to the Thebans, contrary to an oath sworn by the Plataians.81 The Athenians rallied to the aid of Plataia, installing a garrison in the city, and prepared for war with the Peloponnesians, since the attack on their ally constituted a breach of the terms of the Thirty Years’ Peace.82
Theban resentment of Plataian recalcitrance lingered, and the Plataians became a natural target of Peloponnesian attack in the war between Athens and Sparta. The Spartan army arrived in 429, and Archidamos offered to leave the Plataians alone if they would abandon their alliance with Athens and remain neutral throughout the war. The offer was rejected, and the Peloponnesians, with Boiotian help, laid siege to the city.83 The small force at Plataia held out, remarkably, until the summer of 427, when the place was surrendered.84 In the sham trial of the defenders that followed, the Plataians speak only of Theban, not Boiotian, hostility: they accuse the Spartans of being willing “to efface the city, to its very last house, from the whole of Greece for the sake of the Thebans”;85 they fear that the Thebans have persuaded the Spartans to destroy them (Th. 3.58.1); they expect that the Spartans intend to make the Plataian chōra Theban (3.58.5); and they speak repeatedly of the Thebans as their most hated enemies (3.59.2–4).
The Theban response to the Plataians’ defense speech reveals much about the claims the Thebans were making in the mid-fifth century about the past, their attempts to create their own version of Boiotian history, an attempt at ideological leadership to match their attempt at the political leadership of the region.86 Their opening salvo is thus worth quoting in full (Th. 3.61.2):
Differences first arose between us when we founded Plataia later than the rest of Boiotia, and other places with it, which we held after expelling the mixed population. But they did not think they deserved to be ruled by us, as was originally arranged, and so they stood outside the other Boiotians, contravening the traditions of their ancestors [ta patria]. But when they were pressed too severely, they went over to the Athenians, and with them they did us much harm, in exchange for which they also suffered.
The Thebans now claim responsibility for the settlement of all Boiotia, the expulsion of a mixed population upon their arrival from Thessalian Arne (cf. Th. 1.12.3), and some almost primordial position of hegemony within the entire region.87 They claim too that cooperation of the poleis of Boiotia under Theban leadership was ancestral; ta patria is an explicit attempt to place the political movement of the present—toward the greater organization and institutionalization of Boiotian interpolis cooperation under Theban leadership—in the deep past, to justify their aggression on behalf of this cause. It echoes directly the offer made by the Thebans to the Plataians in 431: if they were willing to make an alliance in accordance with ta patria of all the Boiotians, they would not be attacked.88 In the rest of the speech the Theban strategy is to show that the Plataians are staunch allies of Athens and therefore equally staunch enemies of the Peloponnesian alliance in the current war, making the Athenians into latter-day Persians, enslaving the Greeks just as the Persians had once tried to do. In the same vein the Thebans claim that the victory at Koroneia was won in order to bring Boiotia over to the Peloponnesians (3.67.3). For our purposes their more interesting argument is that they were justified in invading the city in 431 because they were invited by Plataians who were prominent both in wealth and in birth “to restore [the city] to the shared ancestral traditions [ta koina patria] of all the Boiotians,” which would have amounted to them “living among kin.”89 Plataia was, in other words, victim as much of its small size and geographical vulnerability as it was of internal stasis, with the oligarchic element favoring participation in a Boiotian regional government and the democratic majority favoring continued alliance with Athens.90 The Plataians’ pleas were unsuccessful, and the city met a brutal end: the defenders were executed by the Lakedaimonians, and the city itself came under direct Theban control, being quickly razed to the ground.91
If the Thebans had by 427 won a position of leadership within Boiotia, they fought hard to retain it within the institutional confines of the koinon established about 446, which by clearly establishing the rights and obligations of each member polis to the koinon restricted the Thebans’ ability to act unilaterally or to efface the local autonomy of the other Boiotian poleis. In 426 they went to the assistance of the Tanagrans who were besieged by a full force of the Athenian army, an attack that started from Oropos (then in Athenian hands) and may have been motivated by the Athenians’ anxiety over controlling the food supply from Euboia to Attica via Oropos.92 Although the Thebans’ assistance was ultimately ineffectual, it does point to their active commitment to the project of a regional state, for Tanagra was an independent Boiotian polis and member of the koinon in this period. And it was probably between 427 and 424 that the Thebans doubled the size of their territory and population by undertaking the synoikism of at least six small communities into Thebes: Erythrai, Skaphai, Skolos, Aulis, Schoinos, Potniai, and many others, the Oxyrhynchos Historian (17.3) tells us. This move was taken partially as a response to mounting Athenian aggression toward Thebes: in the frontier zone between northern Attica and southeastern Boiotia, these small communities were highly vulnerable. They had previously been in sympoliteia with Plataia, so it was ultimately the Theban destruction of that city that exposed them. The synoikism was not an act of Theban beneficence.93 The reorganization of southern Boiotia in the mid-420s reveals how complex the political geography of Boiotia already was: a region, recognized as such in ethnic terms, but only fitfully unified politically, and containing within itself subregions comprising multiple communities in various configurations of dependence and interdependence. This should provide us with an important indication of how and why the koinon came into existence.
But even as the regional government in Boiotia took on firmer and more stable institutions, internal unrest threatened the structure. In 424 democrats within the region, seeking closer Athenian relations and a weakening of this ever stronger and more centralized Boiotian regional state, encouraged the Athenians to invade. The Boiotian democrats, according to Thucydides (4.76.2), wished “to change the order of things and to set up a democracy, just like the Athenians.” They were spread throughout the southern and western part of the region: their leader was a Theban exile, and some Orchomenians and Phokians were also involved.94 These partisans planned three strategic points of betrayal: they would themselves hand over Siphai, the small Corinthian Gulf port of Thespiai, and Chaironeia, while the Athenians were to take the initiative in seizing Delion, a temple of Apollo in the territory of Tanagra.95 Boiotia was thus to be invaded by Athenian and pro-Athenian forces from west, south, and east on the same day, appointed in advance.
But like many well-laid plans this one too was botched. There was confusion about the day on which the attack was to be made, and the plot was revealed