Cleisthenes, born circa 570 BC and referred to as “The Father of Athenian Democracy”, is credited with creating the system that, with incremental reforms, governed Athens during the Classical era. After Peisistratos died in 527 BC, he was succeeded as co-tyrants by his sons Hippias and Hipparchus. The duo governed Athens competently and with a light hand until Hipparchus was assassinated in 514 BC in a private feud stemming from a romance that went bad. After his brother’s assassination, Hippias grew paranoid, and his rule became oppressive as he lashed out indiscriminately at enemies real and imagined.
Hippias’ descent into violence eroded the popularity the tyranny had enjoyed since the days of Peisistratos, as the number of victims and exiles forced to flee Athens grew. One exile was Cleisthenes, who began plotting with other exiles to overthrow the tyranny. Invasion was considered, but Hippias had a well-equipped army, while the exiles did not, and lacked the funds for an army of their own. So they sought to enlist the help of Sparta, which had the Greek world’s best army, to liberate Athens.
To induce help from the Spartans, who were known for their piety, the exiles bribed the priests of Delphi, the Greek world’s most important religious site and home of the Oracle of Delphi. The Oracle, which for centuries had given petitioners cryptic answers that could be interpreted in a variety of ways, suddenly began giving every Spartan petitioner who showed up the same uncryptic answer: “Liberate Athens!“.
So the Spartans marched into Attica in 508 BC, liberated Athens, then marched back home. The Athenians left to govern themselves, immediately split into rival camps: an oligarchic camp led by Isagoras, that wanted government returned to the hands of the wealthy, and a populist camp led by Cleisthenes and comprising a majority of Athenians, which declared Athens a democracy ruled by a popular Assembly.
Cleisthenes’ camp prevailed, but the oligarchic faction solicited Spartan aid to overthrow the democracy. The Spartans, no fans of democracy, sent another army to Attica, overthrew the democracy, and replaced it with an oligarchy. Cleisthenes and 700 democracy-supporting Athenian families were exiled. However, Cleisthenes and the exiles soon returned, the population rose up in revolt, and the aristocratic faction and the Spartans were besieged in the Acropolis, Athens’ fortified hilltop. The rebels allowed the Spartans to leave, but the Athenian anti-democrats were massacred.
Having decisively dealt with the oligarchic threat, Cleisthenes set about establishing the Athenian democracy. The major reform was the reorganization of the citizen body (demos) of Athens. Before, Athenians had been grouped into four tribes, based on kin groups. Cleisthenes argued that such grouping lent itself too readily to factionalism.
Instead, Cleisthenes instituted an artificial classification system that divided the citizen body into ten at-large tribes, with membership drawn at random from all classes and all parts of Attica. With each tribe thus containing a representative sample of the entire population, including all classes and regions, the incentives for parochialism would be eliminated, as no tribe would have cause to act out of geographical or familial loyalties at the expense of Athens as a whole.
A new council, the boule, was created, in which all citizens had the right to speak. At a stroke, Cleisthenes thus eliminated the parochialism that had plagued Athens for generations and granted the entire male citizen population access to institutions and powers previously reserved for the aristocracy. Another of Cleisthenes’ reforms was ostracism, whereby an annual vote would be held in which each citizen could name any person he thought was too dangerous or getting too powerful for the good of the city. The citizen receiving the most votes would be exiled for ten years, without prejudice to his property while he was gone, or to his citizenship rights upon his return.
Cleisthenes’ reforms thus established basic democracy in Athens and created the constitutional structure by which further incremental reforms would be made to transform Athens into a direct democracy.