We tend to think of the Spartans according to the stereotypes about them, such as we get from the speech of the Corinthians at the congress of Peloponnesian allies in 432: in binary contrast to the Athenians, who are quick to action, always innovating, always expanding, the Spartans are portrayed in the highly rhetorical periods of the Corinthian ambassador as slow to act, conservative, and xenophobic (Thuc. 1. 68-71). But the history of Spartan activity in the latter half of the sixth century in some ways belies the stereotype.
In the first half of the sixth century, the Spartans fought a long war with the Tegeans, their neighbours to the north (Hdt. 1. 65-68). This was the war which was brought to a successful conclusion after the Spartans enterprisingly "discovered" the bones of Orestes and brought them to rest at Sparta in accordance with the instructions of the Delphic oracle. This should perhaps be viewed as a foundation legend for the hero-cult of Orestes at Sparta. This war with the Tegeans did not end, as the Messenian wars had, with the complete subjugation of the enemy. Rather the Tegeans were forced into an alliance with this Spartans. This alliance, primarily a defensive alliance against Argos to the east, should be seen as the first step in the formation of the Peloponnesian League. Because the Peloponnesian League formed the kernel of the Panhellenic alliance which resisted the Persian invasion in 481-479, it is worth investigating its development and trying to determine its nature.
The next datable event in the history of the formation of the League is the "Battle of the Champions", fought against the Argives over the plain of Thyrea in c. 544 (Hdt. 1. 82). Once dominance of Argos had been demonstrated, Sparta was able to coerce a number of smaller city-states in the region to form alliances. The measure of Spartan power and prestige at this point is illustrated by the fact that, after the Lydian empire was overthrown by Cyrus (also c. 544), the Greeks of Asia Minor appealed to the Spartans to come to their aid after it became clear that the Great King was not willing to continue relations with them on the same terms they had enjoyed as tributaries of Croesus (Hdt. 1. 141). Herodotus relates an unlikely story that the Spartans sent a herald (Lakrines) to instruct Cyrus in the name of the Spartans not to harm any of the Greek cities of Asia (1. 151-2); this story probably arises from the propaganda of a later time, when Sparta and Athenians were each claiming to be the champions of the freedom of the Greeks of Asia against the power of the Persian king. Although the Spartans did not intervene, if the story has a kernel of truth (i.e. if a request was made) it shows clearly that Sparta was considered the preeminent military power among the Greek states at this time.
The Spartans did intervene, together with their allies the Corinthians, in an attempt to end the oppressive rule of the Samian tyrant Polykrates, who had established a thalassocracy over his immediate vicinity. Herodotus says that this involved "a large force"; we should suppose that the troops were mostly Spartans and that the Corinthians supplied the ships for transport (3. 54-56). We can safely disregard the motives Herodotus assigns for this venture, which have to do with bowls and corselets stolen from the Spartans and Corcyraean boys sent to the Sardis by the Corinthians to become eunuchs; the willingness of the Spartans to intervene in the affairs of Greek states abroad is adequately explained by their opposition to tyranny (as noted by Thucydides, 1. 18) and newly acquired position as head of a powerful League of Peloponnesian cities. The expedition was, however, a failure, and that failure led to the formulation of a new Spartan foreign policy. Henceforth Spartans would almost without exception refuse to intervene to protect like-minded Greeks overseas. The Greeks of Asia Minor were left for the most part to the tender mercies of the Great King. Thus the Spartans created a power vacuum by their withdrawal, and it was only a matter of time before the Asiatic Greeks would be forced to seek a protector elsewhere.
At the same time, the Spartans continued the effort to extend their influence in the Peloponnese and on the mainland. The years c. 520-490 in Spartan politics are dominated by the reign of King Cleomenes. He proved willing enough to go on campaigns well away from the Spartan homeland, though not so far abroad as Scythia (if Herodotus' story of a Scythian request for an alliance after the invasion of Scythia by Darius is credible, 6. 84). He himself seems to regard the tradition about the Scythian overture as a fanciful aetion to explain why the Spartans refer to drinking unmixed wine as "Scythian style". Cleomenes came repeatedly to Attica in the years 510-507, first to expel Hippias and second in support of Isagoras against Cleisthenes and the Alkmaionids. His opposition to Hippias can be partly explained by the same motivation which brought the Spartans to Samos fifteen years before: as Thucydides says, "The Spartans were putting down tyrannies all over Greece" (1. 18). But the Spartans had had friendly relations with the Peisistratids through most of the sixth century, so some further motive is needed. Sealey offers a circumstantial case for supposing that Hippias had angered the Spartans by alienating the Megarians from the Peloponnesian League. If correct, this suggests that the League's policy is expansionist or at least that withdrawal from the League was strongly discouraged. It points us to recognizing the extent to which the Delian League, the alliance which grew out of the alliance against the Persians and which eventually became the basis for the Athenian Empire, based its practices upon those of the earlier Peloponnesian League.
But the quarrel over Megara and Athenian influence in Salamis cannot explain why Cleomenes was willing to invade Attica again in the context of what looks like an internal political dispute, the struggle between Cleisthenes and Isagoras. No better explanation for this is available to modern historians than that offered by Herodotus, that Cleomenes had a personal friendship with Isagoras (though it seems likely that the political objective of Isagoras was a broad-based oligarchy on the Spartan model rather than, as Herodotus says, a tyranny).
Two episodes might suggest that Spartan control over the League was not absolute, that in other words the League took decisions on a joint basis, each state safeguarding its own interest. Herodotus says that after the first attempt to install Isagoras and his supporters failed, Cleomenes organized a three-pronged invasion of Attica, the Chalcidians (Euboeans) and Boeotians invading from the north while a Peloponnesian force marched in from the south; but the Corinthian and other allied contingents changed their mind after reaching Eleusis and left the field. This action might lead one to suppose that they could expect not to suffer retribution from the Spartans for diverging from the policy of the League. However, stress should perhaps be laid upon the existence of a dispute between the two Spartan kings. We know that Cleomenes's co-regent, Demaratus, also decided not to fight at Eleusis, so it may be that the allies rallied around Demaratus and believed that his support would protect them from the charge of deserting the League's forces in action.
Herodotus also describes how the Spartans, after the attempt at invasion failed, proposed to the League that it should take action to restore Hippias at Athens. Supposedly the proposal failed after the Corinthians made a speech to the allied congress illustrating the undesirability of tyranny as a political system. The entire episode is hard to fit in with what we know of Spartan and League policy at the end of the sixth century. Hippias had since shortly after his expulsion and retirement to the Peisistratid enclave at Sigeion been enjoying the protection of the Persians, and the guiding principle of Spartan policy seems to have been that the Persians could do as they pleased in Asia but their acquisition of influence of the Greek mainland was to be checked.
Herodotus' own explanation for why the Spartans are supposed to have changed their minds about Hippias seems at first look highly unsatisfactory (5. 90-91). He says that the Spartans came into possession of certain oracles which indicated that the Athenians were destined to become a power which would challenge their own. The Spartan decision to support the return of Hippias then is supposed to have been intended to weaken this Athenians. This exemplifies two characteristic weaknesses in the way the Greek historians deal with causation. First, the explanation patently fits into the larger principle enunciated by Herodotus at 5. 78, that the true vigor of the Athenians could only be realized under a free political system. Second, Herodotus' explanation uses historical hindsight to explain the event, while at the same time getting in a plug for the veracity of oracles, a favorite hobby-horse of his. He knew that in fact the Athenians had grown into a power which threatened the Spartans. Could it have been apparent in the years c. 500 that the power of the Athenian state was increasing so much as to threaten Sparta's position of supremacy? In the next section we will examine the growth of Athenian power after the deposition of the tyrants.
The true reason for the Spartan desire to restore Hippias seems difficult to recover. It may be that it existed on the personal level only; perhaps one of the kings was bribed to support the Peisistratid cause. Perhaps the impetus came from within Athens itself, where we know support for the Peisistratids was far from extinct.