Solon

Athenian statesman and poet — who was appointed to reform Athens's constitution (594 BCE) — cancelled debt bondage (seisachtheia), reformed the Athenian class system, and created the first Athenian democratic institutions — one of the Seven Sages of Ancient Greece.

Creates the constitutional foundations of Athenian democracy — Solon's reforms (abolishing debt slavery, opening the courts to all citizens, creating the Council of 400) established the institutional prerequisites that Cleisthenes later expanded into full democracy; his refusal to seize tyranny when he had the power is the foundational act of constitutional restraint.