Helen of Troy

Helen of Troy (Ancient Greek: Ελένη) was the Greek demigod daughter of Zeus and the mortal Leda (Some say that Zeus appeared to Leda as a Swan and Helen was born from an egg), queen of Sparta, wife of King Meneleus, and sister of Castor, Polydeuces, and Clytemnestra. Helen also had a daughter, Hermione. Her abduction by Paris brought about the Trojan War. Helen was said to be the most beautiful woman in the world, sometimes even more beautiful than than the goddess Aphrodite.

History
The three Olympian goddesses Athena, Hera, and Aphrodite appeared to Paris and asked him to make a decision on who was the most beautiful goddess. As Paris was unable to decide, the goddess each offered him a gift in return if he chose them. Athena offered all the wisdom in the world as well as good swordsmanship and victory in war. Hera offered him power over Asia minor. Aphrodite offered to give him the most beautiful mortal in the world, Helen. After listening to that, Paris immediately chose Aphrodite, making Athena and Hera outraged, which made them Paris' enemies. This was eventually orchestrated by Eris as Paris claiming Helen for his wife even though she was already married to King Menelaus. This action ended up starting the Trojan War. When Troy fell thanks to the Greeks using the Trojan Horse, Paris was killed and Helen was reclaimed.

The different outcomes of Helen have varied for each story.
 * Some say she was brought up to Mount Olympus upon death by Zeus.
 * Some say she was later hanged by the Furies.
 * Some say she never made it to Troy but Hera, in order to take revenge from Aphrodite, made Hermes kidnap Helen and bring her to Egypt. While Helen was to Egypt, Hera made a fake Helen. After the war was over , Menelaus lost his ship and landed to Egypt. There the fake Helen disappeared and Menelaus and Helen tried to find a way to escape, without the king Theoklimenous taking notice on their escape. Eventually they came up with a plan. Menelaus was going to pretend to be a lost sailor of Menelaus and they would say that Menelaus was dead. Then Theoklimenous gave the real Menelaus a ship and food so he and Helen managed to escape.

The Titan's Curse
Percy briefly mentions Helen when talking to Aphrodite about tragic love stories in a white limo at the Junkyard of the Gods when she is with Ares somewhere in Colorado. Aphrodite sees these tragic love stories as if they were soap operas. She also says she hasn't seen such a tragic love story for centuries, probably referring to Helen and Paris.

The Lost Hero
She is mentioned when Piper is picking out a weapon and picks Helen's knife, Katoptris, which means looking glass, Annabeth reckons that's all it was ever used for, and she doubted it had ever seen war. Later at Aeolus' Palace, Jason mistakes the wind nymph Mellie for a ghost, and Piper covers for him, saying he mistakened Mellie for Helen of Troy, the most beautiful mortal of all time. It seemed a little over the top, but Mellie appeared to buy it.