The Thirty Years' Peace was a treaty, signed between the ancient Greek city-states Athens and Sparta, in the year 446/445 BCE. The treaty brought an end to the conflict commonly known as the First Peloponnesian War, which had been raging since c. 460 BCE.
The purpose of the treaty was to prevent another outbreak of war. Ultimately, the peace treaty failed in achieving its goal, with the outbreak of the Second Peloponnesian War in 431 BCE.