Which Greek states remained neutral or supported Persia during Xerxes’s invasion?

During the invasion of Greece by Xerxes I in 480 BCE, Greek unity was incomplete, and several states chose to remain neutral or actively support the Persian forces.1

• Thebes: Thebes was a prominent example of a state that "Medized," meaning it sided with the Persians.1
• Argos: The neutrality maintained by Argos was viewed by the historian Herodotus as being equivalent to Medism.1
• Thessaly: Thessaly also "Medized," a decision that was often attributed to local rivalries, such as its desire to spite its neighbor and enemy, Phocis, which chose to resist the invasion.2
• Other Boeotian cities: Following the Battle of Thermopylae, the majority of cities in Boeotia joined the Persians, with the notable exceptions of Thespiae and Plataea, which continued to resist.3

While some states were motivated by a desire to spite rival neighbors, others may have simply calculated that submission to the Persian Empire would not significantly alter their day-to-day existence compared to the demands of other Greek powers.2