When did the Athenians and Spartans cooperate with each other?

The Athenians and Spartans cooperated during the Persian Wars, particularly in the battles of Marathon (490 BCE) and Salamis (480 BCE). Despite their rivalry, they united against the common threat posed by the Persian Empire. This collaboration was crucial in securing Greek victories, showcasing their ability to set aside differences for a greater cause. However, this alliance was short-lived, as tensions quickly resurfaced, leading to the Peloponnesian War.