Antalcidas continued in favor with Artaxerxes until the revolting Thebans annihilated Spartan supremacy at Leuctra in 371 BC, diminishing his influence. Plutarch notes a laconic comment made by Antalcidas to Agesilaus after one of the Spartan losses to Thebes, saying in effect, "Isn't it amazing how good they've gotten after all of the training we've given them." That year or possibly in 367 BC, Antalcidas undertook a final mission to Persia. Plutarch held that its failure drove him to starve himself to death.