The Golden Age started when Kronos killed his father Ouranus, and ended in the Titanomachy, when Zeus overthrew the Titans and cast them to Tartarus. Humans who lived in this age are called the Golden Race, who were born from Gaea herself. It was an age where a human lived five-hundred years, and almost as well as the Titans, with Kronos being their supreme leader. In total, the max population of the Golden Age reached 30,000. The most advanced civilization was the one of Atlantis. Though described in the books as a bad time period, it is usually considered the best period in Greek mythology. Humans in those days lived peacefully and in complete health and long-lasting youth, and after a long life, they died peacefully. There was no civilization as the Golden Race acquired anything they wanted by thoughts, and animals spoke in human voices. While the Golden Age was a time of peace, humans were free of knowledge and were no different from animals. The Golden Race died out because no woman had existed before the time of Zeus.
Poseidon Zeus Hades

Poseidon, Zeus and Hades

Percy Jackson and the Olympians

The Lightning Thief

The Golden Age was described as just propaganda by Kronos as in truth he only used humans as either cheap entertainment or as a light snack. It is said it was only after Zeus overthrew Kronos and Prometheus gave man fire, that they began to rise into Western Civilization and became more sophisticated.