In the Archaic period, many Greek cities were ruled by men called tyrants. (In the Classical period, tyrants disappeared from the Greek mainland, though they continued to thrive in the Greek cities of Sicily.) The word, turannos, probably derives from a Lydian word for “monarch”. It is first encountered in a poetic fragment attributed to Archilochus (fr. 19 West), where the warrior-poet explains that he does not care about the life and riches of Gyges, the ruler of Lydia.
We know from Herodotus that Gyges became king of Lydia and founded his own dynasty after killing his predecessor, a man that the Greeks referred to as Candaules, but who was also known, according to Herodotus, as Myrsilus (Hdt. 1.7.2). “Tyrant” became the word by which the ancient Greeks denoted men who had essentially become monarchs in an elicit way, often by simply seizing power.
A. Andrewes, in his influential but outdated monograph The Greek Tyrants (published way back in 1956), claimed that Greek tyrants rose to power through a combination of popular and military support. That’s no longer considered accurate. It seems rather that Greek tyrants arose from stasis (factional strife) among the elite themselves, and that the would-be tyrant sought support among the upper echelons who felt excluded from political power. Hence, the tyranny at Corinth overthrew the dominant Bacchiad clan.
It is a characteristic of tyranny that it never lasted long. Sometimes a man was able to rule until his death, and on rare occasions he was even succeeded, for a while, by his son. In Corinth, the first tyrant was Cypselus, who was succeeded by his son Periander. Cypselus, whose name means “Chest” and whose story is recounted by Herodotus in the form of a pleasant fairy tale, perhaps – and in my opinion – didn’t really exist. His son, though, is more or less securely attested and ruled Corinth until his death in ca. 587 BC. In any event, once tyrants disappeared from the scene, the political system tended to shift to a broader oligarchy.
Archaic Athens, too, suffered from social unrest, especially among the higher echelons. The poet-statesman Solon sought to defuse problems through reforms, though many of the details are hotly contested. Eventually, though, a tyrant rose to power: Pisistratus. Herodotus claims that he tried to seize control of Athens twice before succeeding on his third try: again, this is probably an element invented to lend more drama to the tale (third time’s the charm).
Pisistratus’ rule seems to have been benevolent and, indeed, Athens reached new heights under his leadership. When he died in 528/527 BC, he was succeeded by his eldest son, Hippias, who ruled the city with the help of his brother, Hipparchus. Hippias was not as well liked as his father and it was probably during his rule that the word ‘tyrant’ got the negative connotation that it still has.
You might think that Harmodius and Aristogeiton were freedom fighters who set out to release Athens from the unbearable yoke of tyranny by trying to kill Hippias and his brothers. That is indeed how the story is sometimes presented, but it’s apparently not what really happened. As is often the case (and not just in ancient Greece), the reasons that Harmodius and Aristogeiton had in slaying the tyrant were entirely personal.
In 514 BC, according to Thucydides (6.56–59), Hipparchus had made advances toward Harmodius, but these went unanswered. Out of spite, Hipparchus insulted Harmodius’ sister by inviting her to a festival and then chasing her off after accusing her of not being a virgin. Angered, Harmodius and his lover Aristogeiton swore to kill both Hipparchus and his brother. They first approached Hippias, but feared that their plot had been discovered. Leaving the scene, they happened across Hipparchus and hastily killed him. Harmodius was slain on the spot, presumably by bodyguards. Aristogeiton managed to elude capture for a while, but was eventually taken in and executed.
A few years later, Cleomenes of Sparta overthrew Hippias. The Alcmeonid family, who had been exiled from Athens by Pisistratus, returned. Clisthenes, a prominent member of the family, introduced democracy in Athens a little later. As this system of government was new, it was felt it would take root more easily if it had its own heroes, and soon enough Harmodius and Aristogeiton were heralded as tyrannicides, despite not actually having killed Hippias.
After being ousted, Hippias ended up in Persia. One of the things that the Persians wanted to do in 490 BC was conquer Athens and re-install Hippias as the city’s ruler. The Persian defeat at Marathon prevented this from happening.