The naval battle of Salamis 480 BCE destroyed the Persian naval supremacy, removing the amphibious threat to the cities which kept the cities' armies at home defending them, and able to be picked off one by one. It also exposed the essential Persian sea-supply line, and they had to sent half their army home.
As a result, the Greek cities were able to concentrate at Plataia 479 BCE and defeat the depleted Persian army, simultaneously destroying the rump of the Persian fleet at Mykale.
The most important during the 50 years of war which turned the result was the defeat of the Persian navy at Salamis in 480 BCE
The Korean War was the most important event in the 1950s as a hot spot in the cold war.
Japan's attack on Pearl Harbor,and Americans reply as atomic bombs was the most important event
The Ionian city-states revolted against Persian rule.
For Southeast Asia, the Vietnam War.
The most important battle was Vicksburg - liberating the Mississippi and ending the war in the west. The most important event was the Emancipation Proclamation, because it kept Britain and France from sending aid to the Confederates.
Persian War 499-449 BCE. then Peloponnesian War 431-404 BCE.
Next event after what? Without more information, this question is unanswerable.
the battle of thermoply Thermopylae was in the Second Persian War when Athens and Sparta were on the same side. The most important battle in question was the Siege of Syracuse.
The most recent war in the Persian Gulf was the Iraq War of 2003-2011.
D-Day was possibly the most important event of the war in Europe.
1. The people of the Greek city-states who banded together to resist the Persian attempt to keep them within the Persian Empire. 2. The people of the Persian Empire who manned the land and naval forces to prosecute the war.