The second Persian invasion of Greece (480–479 BCE) occurs during the Greco-Persian Wars, as King Xerxes I of Persia seeks to conquer all of Greece.

The invasion is a direct, if delayed, response to the defeat of the first Persian invasion of Greece (492–490 BCE) at the Battle of Marathon, which ends Darius I's attempts to subjugate Greece.

After Darius's death, his son Xerxes spends several years planning for the second invasion, mustering an enormous army and navy.

The Athenians and Spartans lead the Greek resistance, with some 70 city-states joining the 'Allied' effort.

However, most of the Greek cities remain neutral or submit to Xerxes.The invasion begins in spring 480 BE, when the Persian army crosses the Hellespont and marches through Thrace and Macedon to Thessaly.

The Persian advance is blocked at the pass of Thermopylae by a small Allied force under King Leonidas I of Sparta; simultaneously, the Persian fleet is blocked by an Allied fleet at the straits of Artemisium.

At the famous Battle of Thermopylae, the Allied army holds back the Persian army for seven days, before they are outflanked by a mountain path and the Allied rearguard is trapped in the pass and annihilated.

The Allied fleet has also withstood two days of Persian attacks at the Battle of Artemisium, but when news reaches them of the disaster at Thermopylae, they withdraw to Salamis.After Thermopylae, all of Boeotia and Attica fall to the Persian army, who capture and burn Athens.

However, a larger Allied army fortifies the narrow Isthmus of Corinth, protecting the Peloponnesus from Persian conquest.

Both sides thus seek out a naval victory which might decisively alter the course of the war.

The Athenian general Themistocles succeeds in luring the Persian navy into the narrow Straits of Salamis, where the huge number of Persian ships become disorganized, and are soundly beaten by the Allied fleet.

The Allied victory at Salamis prevents a quick conclusion to the invasion, and Xerxes, fearful of becoming trapped in Europe, retreats to Asia, leaving his general Mardonius to finish the conquest with the elite of the army.The following spring, the Allies assemble the largest ever hoplite army, and march north from the isthmus to confront Mardonius.

At the ensuing Battle of Plataea, the Greek infantry again proves its superiority, inflicting a severe defeat on the Persians, killing Mardonius in the process.

On the same day, across the Aegean Sea, an Allied navy destroys the remnants of the Persian navy at the Battle of Mycale.

With this double defeat, the invasion is ended, and Persian power in the Aegean severely dented.

The Greeks now move over to the offensive, eventually expelling the Persians from Europe, the Aegean islands and Ionia before the war finally comes to an end in 479 BCE.