Did Athens or Sparta made the government changed from an oligarchy to a democracy?

Athens is credited with the transition from oligarchy to democracy, particularly during the 5th century BCE under the leadership of figures like Cleisthenes and Pericles. This shift involved the establishment of a system where citizens had a direct say in political decisions, contrasting with Sparta's rigid oligarchic and militaristic structure. While both city-states had influential governance models, it was Athens that pioneered democratic principles that would later influence political thought around the world.