Of the areas of the Peloponnese considered here only Corinth and Achaea sent out colonies that can be securely dated to the archaic period. Other foundations, some from other areas, might also belong to the same period - e. g. the four Elean colonies in Epirus (Funke et al. in Inventory nos. 88, 90, 94, 104) - but cannot be dated accurately enough. Corinth founded Syracuse (733), Corcyra (706), Ambracia and Anactorion in Acarnania (650-625), Leucas (650-625) and Apollonia (600) in the Adriatic, and Potidaea in Chalcidice (600). Corinthians were also involved in the foundation by Corcyra of Epidamnus/Dyrrachium in the Adriatic ca. 625. The Achaean foundations were all in southern Italy: Croton (709/8), Sybaris (co-founded with Troizen in the late eighth century), Metapontium (630), and Pandosia (sixth century).38 It is clear that, with the notable exception of Potidaea, both Corinth and Achaea colonized in the west. In other respects, however, the patterns of their colonization are very different.
From the eighth century Corinth was well organized and already engaged on a significant export trade. The most obvious evidence of Corinth’s export is the Corinthian pottery found at many sites, particularly among western Greeks and neighboring areas (Salmon 1984: 101-16). Corinthian colonization created settlements in the Adriatic, southern Italy, and Sicily, but Corinth, initially at least, kept some control of these new communities, appointing reliable men in charge, and evidently expected the colonies to foster Corinthian interests in the area.39 The situation in Achaea was quite different: the polis seems to have emerged in the region relatively late, and it is unclear what links there were among the various archaic communities of Achaea. It is consequently unclear who the “Achaeans” were who sent out the colonies. It does however seem clear that the Achaean colonies developed faster and became more prosperous than the settlements of Achaea itself.40
Colonization shows the strength of the archaic Peloponnese’s connections to the west (also seen e. g. in the treasuries set up by western Greeks at Olympia, see below), but it also shows how Peloponnesian regions varied: several did not colonize at all, and Corinth and Achaea, which did, produced different patterns of colonization.41
The Peloponnese was home to no fewer than three of the so-called Panhellenic sanctuaries: Olympia, Isthmia, and Nemea, where athletic games took place and came to attract competitors from all over the Greek world. The most prestigious games were of course the Olympics (supposedly founded 776: Lee 1988), but the games at the two other sites were sufficiently important to be incorporated, with the Olympics and the Pythian Games, into the periodos in the early sixth century: this was a formal arrangement whereby these four festivals were made to follow each other in fixed order.42 The promotion of these four above the innumerable local athletic festivals throughout the Greek world43 shows clearly that they were of outstanding importance and that in this respect the Peloponnese was at the heart of Greek interaction. Due to their enormous prestige (Golden 1998: 33-7, 80-1), the history of the Olympics is far better known than that of the Nemean or Isthmian Games. The archaic catchment area of the Olympics is illuminating: cities of the Peloponnese itself, of course, were blessed by victories of their citizens,44 but a large number of victors came from outside the Peloponnese, from Sicily, Magna Graecia, the Adriatic, Phocis, Boeotia, Aegina, Athens, Euboea, East Locris, Thessaly, Ionia; in short, from most parts of the Greek world.45
But Olympia was not only a meeting place for athletes: it was an important centre of interaction and display for the city-states of archaic Greece. So city-states would post important acts of state there in the form of inscriptions, thus adding Zeus’ sanction to the act. But that was presumably not all: for instance, display of interstate treaties served to announce new loyalties and to show strength on the part of the senior parties to such treaties (Lewis 1996: 140-2). The patron of the Olympic sanctuary, Elis itself, as explained above, was a polis which expanded its power to the detriment of lesser communities, and Elis naturally used Olympia to publish its treaties: a treaty of ca. 500 between Elis and an otherwise unknown community, the Ewaoioi, with Elis as the leading power, was published at Olympia, obviously as a show of strength to the international gathering flocking there (ML 17; Roy and Schofield 1999). So was the mid-sixth-century treaty by which the powerful polis of Sybaris - a western colony founded from Achaea - announced the entry into its hegemonic league of a new ally, the obscure Serdaioi (ML 10; Fischer-Hansen et al. in Inventory 296).
By publishing such treaties, then, communities displayed their stature and affirmed their place in the Greek world. Naturally, however, similar statements could be made by dedications. For example, “an unparalleled collection of arms and armour” (Snodgrass 1999: 12) has been found in the German excavations; they certainly originally belonged to dedications whereby a victorious belligerent offered part of the spoils taken from the defeated enemy to Zeus Olympios. Such dedications were probably not prompted only by piety: as pointed out by Snodgrass, they were intended to communicate with other communities and will “have impressed the citizens of other poleis with the prowess of one’s own.”46 Victory dedications could also take the form of sculpture financed by spoils, as when Arcadian Kleitor in 550-500 dedicated a figure of Zeus from booty taken “from many poleis.”47 But dedications took an even more monumental form: on the northern edge of the Altis, the Olympian temenos, below the Kronion hill, is the so-called Terrace of Treasuries. A treasury (thesauros) was a small temple-like building erected by an individual polis as a gift to Zeus, the god of the sanctuary. On the terrace are remains of twelve such treasuries; a few may be early fifth century, but the bulk is archaic. The Megarian treasury preserves remains of magnificent pedimental sculpture (Bol 1974) and all in all these are splendid dedications. What is particularly notable is that most of these were erected by western colonies: Syracuse, Epidamnus, Sybaris, Selinous, Metapontium and Gela. As pointed out above, Peloponnesian colonization was primarily directed towards these areas and the treasuries are traditionally, and obviously correctly, interpreted as monumental expressions of the colonies’ efforts to maintain contacts with the old homeland and, importantly, to define themselves as Greeks. The Olympic sanctuary, then, developed into one of the nodal points of Panhellenic interaction and so, no doubt, did the sanctuaries at Nemea and Isthmia.