The Persian Wars of 490 and 480 BC are known as the heroic struggle in which the Greeks united to resist the invasion of the expanding Persian Empire. Yet, later historical writings reveal that the Greeks did not stand together in unity, as political interests and rivalries divided them to the point that, in battle, there were also Greeks who fought against other Greeks.
In the collective mind, the battles of Marathon, Thermopylae, Salamis, and Plataea have become symbols of Greek courage and bravery. However, the Greek world was not a single nation united against Persia. It was divided into hundreds of independent poleis, communities with competing political interests, rivalries, and objectives. During the Persian invasions, some Greeks actively fought alongside the Persians, while others initially resisted but later submitted under pressure.
The most notable of these were the Thessalians, Thebans, and other Boeotians, as well as smaller communities in central Greece. Their actions demonstrate that the Persian Wars were not simply a war between “Greeks” and “Persians” but also a conflict in which Greeks fought against Greeks on occasion.
Greeks and the Persian Wars: “Earth and water”
The historian Herodotus, a principal ancient source for the Persian Wars, explicitly recorded the Greek communities that accepted Persian demands. When Xerxes requested the traditional tokens of submission, “earth and water,” Herodotus listed “the Thessalians, Dolopians, Enianians, Perrhaebians, Locrians, Magnesians, Melians, Achaeans of Phthia, Thebans, and all the Boeotians except the men of Thespiae and Plataea.” This list is noteworthy because it immediately challenges the idea of a united Greek resistance. Some communities regarded cooperation with Persia as the best way of preserving themselves, while others viewed the Persian invasion as an opportunity to defeat local rivals.
The Thessalians are perhaps the clearest example of the complicated motives behind “Medism,” the ancient Greek term for cooperation with Persia, derived from the Medes, an ancient Iranian people whose kingdom was incorporated into the Persian Empire in the 6th century BC. The Greeks commonly used the name “Medes” when referring to the Persians.
Thessaly was politically divided, and the powerful Aleuadae family of Larissa supported the Persians. Herodotus wrote that the Thessalians initially attempted to join the wider Greek resistance but only on the condition that other Greeks would send sufficient forces to defend Thessaly. Their representatives warned the Greek alliance: “if you will not send help, there is no constraint that you can put upon us.” When the promised support proved inadequate, Thessaly submitted.
This episode is significant because it shows that Thessalian collaboration was not necessarily motivated by admiration for Persia. Herodotus himself stated that the Thessalians had originally sided with the Persians “not willingly but of necessity.” Modern scholars likewise warn against treating all Greek collaborators as ideological supporters of the Persian Empire. The Oxford Classical Dictionary notes that the motives for Medism are rarely stated by the sources and argues that fear of attack and hostility toward Greek rivals may have been more important than admiration for Persian culture. In other words, Greek states could cooperate with Persia because they considered it politically advantageous or simply because resistance seemed impossible.
The Thessalian decision nevertheless had military consequences. Once the Persians entered Greece, Thessalian leaders helped facilitate their advance. Herodotus later described Thorax of Larissa as having “opened a passage for Mardonius into Hellas.” Thessalian cavalry also participated in Persian operations. Thus, a Greek community that had initially sought protection from the wider Greek alliance eventually became part of the Persian military system. Greek soldiers could therefore find themselves fighting other Greek soldiers because their cities had chosen opposing political strategies.
The Thebans: The most prominent supporters of the Persians
The most famous Greek collaborators were the Thebans and the wider Boeotian communities. The situation there was particularly complicated because not every Boeotian city supported Persia. Herodotus carefully distinguishes the Thebans and most Boeotians from Thespiae and Plataea, which resisted the Persians. This distinction is important, as “Boeotia” was not politically unified, and the Persian invasion intensified existing local rivalries.
At the Battle of Plataea in 479 BC, these divisions became especially dramatic. The Thebans fought on the Persian side against the Greek coalition commanded by Sparta and Athens. Herodotus describes them as fighting “in their zeal for the Persian part,” repeatedly directing their cavalry against the Greek army. Their participation was not merely symbolic. They supplied troops and actively fought against other Greeks.
The Theban connection with Persia was also political. Before the Battle of Plataea, Theban leaders advised Mardonius to avoid a direct confrontation and instead exploit divisions among the Greeks. According to Herodotus, they argued that if the Greeks remained united, “it would be difficult even for the whole world to overcome them by force of arms,” but that Persia could defeat them by exploiting their disagreements. The statement is revealing because it identifies the central weakness of the Greek resistance: its lack of unity. Persia’s greatest advantage was not simply its enormous army but its ability to exploit rivalries among the Greek states.
The Phocians were coerced to fight against other Greeks during the Persian Wars
The Phocians illustrate another dimension of Greek cooperation with the Persian army—that of coercion. According to Herodotus, the Phocians had “espoused the Median cause warmly” but immediately qualifies this by explaining that they did so “very much against their will.” When Mardonius later threatened the Phocian troops, their commander Harmocydes encouraged them to resist. He told them that they should prove “that they whose slaying they have devised are men of Hellas.” The episode demonstrates why the category of “Greek traitor” must be used cautiously. Some communities were forced into Persian service and did not necessarily share the political goals of their rulers.
There were also Greek states that did not fight for either side. Argos, for example, remained neutral during the invasion, partly because of its intense rivalry with Sparta. Modern scholars emphasize that the later Greek memory of the Persian Wars simplified this complicated political landscape. A recent Cambridge study observes that only a relatively small proportion of Greek poleis actually participated in the defense of Greece and notes that the surviving sources often obscure the roles of those who “stood aloof” or cooperated with Persia. The image of “the Greeks” fighting collectively was therefore partly a product of post-war memory.
This is particularly important because Herodotus himself wrote after the Greek victory and was interested in presenting the conflict as a struggle between freedom and Persian domination. He nevertheless preserved evidence of Greek divisions. His account shows that Greek identity existed alongside intense political fragmentation. Indeed, the Persians themselves comprehended this weakness. The Persian strategy was essentially to break Greek unity through diplomacy, financial means, and local rivalries. At Plataea, the Persians relied upon Greek troops from Boeotia and elsewhere, demonstrating that the invasion was partly sustained by Greeks themselves.
From rivalry to unity
The concept of Medism therefore deserves careful interpretation. It did not necessarily mean that Greeks abandoned their cultural ties or consciously rejected everything Greek. Rather, as the Oxford Classical Dictionary explains, the term generally referred to states or individuals who voluntarily supported or cooperated with Persia in connection with the Persian invasions, while their motives varied considerably. The modern historian must therefore distinguish between ideological support for Persia, pragmatic submission, political opportunism, and military coercion.
Ultimately, the Persian Wars were fought between the Persian Empire and a divided Greek world even though internal conflicts arose during the wars to the point that some Greek city-states cooperated with the invader. Yet these choices cannot be reduced to a simple division between patriots and traitors. Greek states acted according to their own security concerns, rivalries, and political interests. Some supported Persia willingly, others were compelled, and still others remained neutral.
However, the Persian invasion ultimately helped strengthen the understanding of the common Greek identity precisely because the Greeks had been so divided. The later memory of the decisive victories at Marathon, Salamis, and Plataea emphasized unity, even though Greeks fought other Greeks throughout the conflict. The Persian Wars reveal not only the military strength of the Greek city-states but also their political fragmentation. Greek victory was ultimately achieved not because all Greeks united but because enough Greek states were able to overcome their rivalries when they recognized that the Persian threat endangered them all.
See all the latest news from Greece and the world at Greekreporter.com. Contact our newsroom to report an update or send your story, photos and videos. Follow GR on Google News and subscribe here to our daily email!
