The Battle of Salamis was a naval battle fought in 480 BC, between an alliance of Greek city-states under Themistocles, and the Achaemenid Empire under King Xerxes. It resulted in a decisive victory for the outnumbered Greeks. The battle was fought in the straits between the mainland and Salamis, an island in the Saronic Gulf near Athens, and marked the high point of the second Persian invasion of Greece. It was arguably the largest naval battle of the ancient world, and marked a turning point in the invasion.

The Achaemenid Empire or Achaemenian Empire, also known as the First Persian Empire, was the ancient Iranian empire founded by Cyrus the Great of the Achaemenid dynasty in 550 BC. Based in modern-day Iran, it was the largest empire by that point in history, spanning a total of 5.5 million square kilometres. The empire spanned from the Balkans and Egypt in the west, West Asia as the base, the majority of Central Asia to the northeast, and the Indus Valley to the southeast.