Final answer:
Achilles mother, Thetis, hid him on the island of Skyros disguised as a woman to keep him from joining the Trojan War, ultimately exposing himself when Odysseus tricked him with weapons.
Step-by-step explanation:
When Achilles' mother, Thetis, sought to keep him from going to Troy, she disguised him as a woman and hid him on the island of Skyros in the court of King Lycomedes among the king's daughters. This subterfuge was designed not only to conceal Achilles' identity but also to prevent him from joining the Trojan War, which was predicted to lead to his early death. Achilles's disguise was ultimately penetrated when Odysseus tricked him into revealing his true nature by presenting a selection of gifts, including weapons, to the princesses. Achilles, enthused by the weapons, cast off his disguise on the spot, thereby revealing his true identity.