When Cleisthenes returned from exile to Athens in the year 507 BC, he faced a situation for which there was no precedent in history. Having proposed reform before Isagoras usurped power, he now had to make good on his promises and forge a government that genuinely reflected the will of all Athenians; aristocrats and commoners.
His solution was to form a general assembly of all Athenian free men, with each man having one vote - a type of government we now call direct democracy. These men would then meet regularly to discuss and vote on all aspects of their city, from the price of olives to the raising of taxes and declarations of war. Though we do not know for sure, it was probably Cleisthenes who established the Pnyx, the small hill in the shadow of the Acropolis, as the location of this general assembly.
The impact of Cleisthenes' reforms was felt almost immediately, revolutionizing all aspects of Athenian life. Democracy released unheard of potentials in its citizens and ushered in an age of achievement and prosperity.
What happened to Cleisthenes after instituting his reforms is, however, a mystery.
The Reforms of Cleisthenes - the tribes