No information on Zakynthos has come down to us on the beginnings of the historical period, beyond the certainty that the island did not take part in the Persian Wars of the sixth century BC. This is inferred from Herodotus' account of two Lacedaemonian traitors, Dimaratos and Igisistratos, trying to take refuge on Zakynthos. The first of them was expelled from the island by the Zakynthians, and the second was handed over to his fellow countrymen.
During the years of the struggle for supremacy between the two great powers of Greece, Athens and Sparta, which preceded the Peloponnesian War between them and their allies, the inhabitants of Zakynthos at first allied with the Lacedaemonians. But around 456 BC the Athenian fleet, under its commander Tolmidis, laid waste the Laconian shores and forced the Zakynthians, as well as other allies of Sparta, to join with Athens. When armed hostilities broke out between Kerkyra (Corfu) and Corinth, which were one of the immediate causes for the subsequent war, Zakynthos sent a thousand soldiers to the assistance of Kerkyra. They distinguished themselves by their valour and helped win the sea battle of 434 BC, which took place off Lefkimi on the coast of Corfu.
When the Peloponnesian War (431-404 BC) was declared, Zakynthos was firmly on the side of Athens. When the Lacedaemonians had recovered from the early defeats inflicted on their naval forces by Athens and had begun to bllild Up a proper fleet, they sent the Spartan general Knymos with a hundred ships to conquer Zakynthos in 430 BC. His sizeable fleet notwithstanding, Knymo was obliged to withdraw in the face of strong resistance.
Next the Zakynthians are known to have sent ships and warriors to join the strong Athenian fleet in the Sicilian campaign in 415 BC (the last major phase of the Peloponnesian War), which ended with the crushing defeat of the Athenians in 413. The Athenian alliance fell apart shortly afterwards, and Zakynthos once more found itself under Lacedaemonian domination. It even exchanged its democratic constitution for an oligarchic one. However, by the time of the treaty between the Athenians and the Lacedaemonians of 371 BC, Which stipulated as a basic condition the autonomy of all Greek cities, Zakynthos had discovered its freedom and its democratic rule.
During the Macedonian wars (215-205 and 200-197 BC), Zakynthos tried again to remain neutral, just as it had done in the Persian Wars. It did not succeed. The island fell first to the Macedonians, then to the Romans, and then again to the Macedonias, who eventually gave Zakynthos to King Aminandras of the Athamanol.