Democracy finds its origin in the serious crisis of the Greek city and the changes specific to Athens:
Wave of Impoverishment
From the 7th century, more and more peasants are condemned to be slaves because of debts. As trade grows, so does competition. Great Greece competes with Greek peasants, it can produce inexpensive cereals (land better suited for agriculture, flat plains, etc.). the Greek peasants work but they cannot earn enough to live. So they get into debt, end up being expropriated and become slaves.
In the cities, this slave labor competes with craftsmen, which also triggers a wave of unemployment.
These serious social crises are followed by revolutions. The oligarchs put down these revolutions with executions and exiles.
The hoplite revolution
In the 6th century, coinage appeared, coming from the barbarian king of Lydia, Croesus, who was in close contact with the Greek cities before his defeat in 546 against the Persian king Cyrus. Each Greek city seized on this notion to mint its own currency, which became a component of the national identity. Thus in the 5th century, the Greek cities no longer minted coins irregularly and each affixed a particular sign to the coinage it minted, the epicene, which made it possible to recognize it. For the Athenian currency, it is an owl.
This fabulous revolution occurs in accordance with the extraordinary development of Mediterranean trade. Thus a new class of wealthy citizens, made up of traders and craftsmen (potters), was born. These citizens are now rich enough to buy hoplite equipment:war is no longer the preserve of the aristocracy. The aristocratic system based on agrarian property was undermined by the egalitarian demands of these new citizen-soldiers. We speak of a hoplitic revolution. This new configuration of social power relations gave rise in particular to two distinct models, destined to oppose each other in the century to come:the Spartan military oligarchy and the Athenian democracy.