Cleisthenes is known for introducing the first form of democracy in ancient Athens around 508-507 BCE. Often referred to as the "Father of Athenian Democracy," Cleisthenes implemented significant reforms that established a system in which citizens could participate directly in political decision-making. He reorganized the political structure by creating new legislative bodies and ensuring broader representation, empowering the citizenry to influence laws and government actions. His reforms laid the groundwork for the democratic principles that would influence future societies, making Athens a model of governance for centuries to come.