|“||The Labyrinth is treacherous. There is only one thing that saw me through: the love of a mortal girl. The string was only part of the answer. It was the princess who guided me.||”|
Theseus' mother, Aethra, was a daughter of King Pittheus of Troezen. When Aegeus, king of Athens, arrived in Troezen, he confided in Pittheus he did not understand the meaning of a prophecy which he had received from the Oracle of Delphi. (King Aegeus had been unable to sire an heir and sought advice from the Oracle of Delphi, who gave him a cryptic and vague explanation). Pittheus, having immediately understood the prophecy, soon devised a plan to provide the aging king an heir - he threw a party, and when Aegeus grew drunk (his wine was purposely left unmixed), Pittheus introduced him to his daughter, Aethra, as the two then proceeded to lie with each other. (Aethra would also lie with the god Poseidon later that night). When Aegeus found out that Aethra was pregnant, he decided to return to Athens. He placed his sword and sandals under a rock, and told Aethra that when their son grew up, he should retrieve the items under the rock and bring them to Aegeus' court to claim his birthright. Having said so, Aegeus returned to Athens.
Aethra named her son Theseus, who was raised at as prince of Troezen innhis grandfather's house. After Theseus grew up, he retrieved the sword and sandals from under the rock. His mother told him about his birthright. Theseus left for Athens with his father's items.
On his way to Athens, Theseus encountered and defeated six rogues: Periphetes (the clubber), from whom Theseus took his club, Sinis (the bender of pines), Phaea and the Crommyonian Sow (a big pig monster), Sciron (pushed his victims from cliffs and fed them to his turtle), Cercyon (the wrestler), and Procrustes (the stretcher) in that order. He killed all the villains by doing the same thing they did to their victims, except Phaea and her sow.
When he arrived at Athens, Theseus did not introduce himself immediately, and his father was suspicious of the stranger. However, Medea, whom the king had married on believing her empty promises of giving him an heir, recognized him and worried that Theseus would be given the crown instead of her son Medus. She challenged him to capture the Marathonian Bull to prove himself. Theseus returned to Athens victorious, whereupon a banquet was thrown in his honor. Medea once more planned to kill the young hero, this time by poisoning his wine cup. At the last second, King Aegeus recognized the sandals, shield and sword that Theseus was wearing as the ones he had left under a boulder for his son. He promptly knocked the poisoned wine out of Theseus' hands, and Medea fled. Father and son were promptly reunited, and Theseus was recognized as Aegeus' son and heir.
The Minotaur and Ariadne
Crete and Athens had a really bad relationship with each other because the son of King Minos was once assassinated in Athens. Minos then brought his whole fleet and nearly completely destroyed the city. He promised to spare the city on the condition that Athens would send seven of the most beautiful maidens and seven of he bravest young men as tributes to Crete so that they could be brought into the Labyrinth and killed.
On the third occasion, Theseus volunteered to slay the monster. He took the place of one of the youths and set off with a black sail, promising to his stepfather, Aegeus, that if successful he would return with a white sail. Like the others, Theseus was stripped of his weapons when they sailed. On his arrival in Crete, Ariadne, King Minos' daughter, fell in love with Theseus and, on the advice of Daedalus, gave him a ball of thread. This was so he could find his way out of the Labyrinth. That night, Ariadne escorted Theseus to the Labyrinth, and Theseus promised that if he returned from the Labyrinth he would take Ariadne with him as she hated it in Crete. As soon as Theseus entered the Labyrinth, he tied one end of the ball of string to the door post and brandished his sword which he had kept hidden from the guards inside his tunic. Theseus followed Daedalus' instructions given to Ariadne; go forwards, always down and never left or right. Theseus came to the heart of the Labyrinth and also upon the sleeping Minotaur. The beast awoke and a tremendous fight then occurred. Theseus overpowered the Minotaur with his strength, tore the Minotaur's horn off and stabbed the beast in the throat with it's own horn(according to one scholium, Theseus strangled it on Pindar's Fifth Nemean Ode).
After decapitating the beast, Theseus used the string to escape the Labyrinth and managed to escape with all of the young Athenians and Ariadne as well as her younger sister Phaedra. On the return journey Theseus, abandoned Ariadne on the island of Naxos, some myths say because Athena told him to in a dream, where she was eventually found by the god Dionysus who fell in love with her and made her immortal. Ariadne then cursed Theseus to forget to change the black sail to white, though some myths say he forgot all by himself or he was grieving about leaving her behind. Seeing a black sail, Theseus' stepfather Aegeus thought Theseus had died and committed suicide by throwing himself into the sea (hence named Aegean). Theseus and the other Athenian youths returned to Athens safely, with Theseus inheriting the crown. He later claims in The Battle of the Labyrinth that he very much wanted to bring back his stepfather from the Underworld, but was unable to do so. Now that he was king, Theseus decided to marry Phaedra.
Theseus would later defeat wild centaur tribes and fight the Amazons. At one point, he also welcomed the wandering Oedipus into his kingdom.
In his later years, however, Theseus fell into bad company with Pirithous (King of the Lapiths), and became far more reckless and villainous than ever before. He became a tyrannical king, best friends with Pirithous and, seeking to marry a daughter of Zeus, kidnapped a 13-year-old Helen of Sparta (this was long before Paris), deciding to hold onto her until she was old enough to marry him (Helen escaped later however). Theseus once had a relationship with Hippolyta, the queen of the Amazons, and they had a son named Hippolytos. Pirithous also wanted a beautiful daughter of Zeus as a wife, but he chose a much more unattainable one - Persephone herself. Leaving Helen with his mother, Aethra, Theseus and Pirithous traveled to the Underworld. An enraged Hades, however, called the Furies to punish both heroes. When they sat down to drink, Pirithous had turned to stone and cracked while Theseus's bottom was stuck to the ground. While Theseus was eventually freed by Hercules a few months later (during the completion of his twelfth labor), Pirithous stayed there for eternity, since he had committed too great a crime for wanting the wife of one of the Big Three as his own bride.
Even after freedom, Theseus eventually grew unpopular. What caused him to leave Athens and have the gods lose faith in him was killing Hippolytos, his own sons, because he was flirting with Phaedra, due to the goddess Aphrodite, who sought to punish the latter for his aromantic asexuality. Then Theseus tried to gain fame in Skyros, but he was brought court and thrown off a cliff where he perished.
Theseus is mentioned by Percy Jackson about how he defeated the Minotaur and Procrustes.
Dionysus stops Percy Jackson on Blackjack while they were following Thalia Grace, Grover Underwood, Zoë Nightshade and Bianca di Angelo. Dionysus tells Percy that you can never trust heroes because of the account that Theseus "dumped" Ariadne on the island Naxos, betraying her. Because she was beautiful, Dionysus healed her broken heart and married her.
Theseus' soul appeared while Nico di Angelo was trying to summon Bianca's soul. Percy thought that Theseus had been a "middle-aged, buff guy" until he saw his ghost, which surprised him. He looked about the same age as Percy which at that time was 14. The ghost states that Aegeus was his stepfather and he recognizes King Minos next to Nico.
He is briefly mentioned by Paul Blofis and Nico while they are discussing how Percy will send a signal to his mom and Mr. Blofis if he defeats Kronos. More specifically, Blofis suggests, "Like Theseus. He was supposed to raise white sails when he came home to Athens," to which Nico replies, "Except he forgot, and his stepfather jumped off the palace roof in despair. But other than that, it was a great idea."
Theseus is mentioned by Hazel Levesque when she and Jason Grace encountered Sciron on the coast of Croatia. Sciron mentions that Theseus was a "cheater" and he did not want to talk about it. Later, Theseus is mentioned by Hazel when she taunts Pasiphaë on how she'll always be defeated by demigods, citing how he killed her son, the Minotaur, and stole her daughter, Ariadne, as a perfect example. This made Pasiphae enraged.
When Nico summons Theseus' soul in The Battle of the Labyrinth, it takes the form of a 14-year-old boy in Greek armor , with long curly dark hair and Poseidon's sea-green eyes, with a seashell-shaped clasp on his cloak. According to Percy, his voice sounded "like dry, crumpling paper", with his eyes "as lifeless as glass."
Being a man with ADHD, Theseus had problems. He was very willing to take risk going through extreme dangers. He was brave and cared for other people getting hurt, creating a philosophy on only attacking when attacked. But Theseus abandoned that philosophy after meeting Pirithous. He was willing to do dangerous and bad things but not even thinking first. But Theseus seemed to learned from his mistakes in The Battle of the Labyrinth, he even tried to persuade Nico not to suffice his same fate.
- ADHD: Like most demigods, Theseus possessed inborn supernatural battle reflexes and senses that he used to analyze the fighting style of his opponents. In Percy Jackson's Greek Heroes, Percy describes Theseus as the super-caffinated kid and the deficit demigod. Indicating that Theseus is extremely ADHD, even for a demigod.
- High Intelligence : Theseus used his wits and cunning to defeat opponents who transcend his physical strength. Percy describes Theseus as "a really smart dude" and as "a genius" when it comes to some things, especially battles.
- Hydrokinesis: In Percy Jackson's Greek Heroes, it is mentioned that Theseus once went underwater without problems. In mythology, Minos threw his ring into the sea and asked Theseus to retrieve it to prove that he is a son of Poseidon.
- Superhuman Strength: Being a demigod, Theseus was stronger than the average mortal. Theseus was physically strong enough to wrestle with and overpower foes as mighty as Procrustes and the Minotaur. He was able to easily carry Periphetes's club, which was covered with about 20 sheets of solid bronze. He had also held the buff king, Cercyon over his head, and dropped him on his knee killing him instantly. Theseus had even managed to slung the Marathonian Bull on his shoulders, which Percy has stated, had weighed 500 pounds.
- Fighting Skills: Theseus was an extremely skilled warrior, even inventing the combat art of pankration with Hercules. He was also skilled in hand to hand combat, as he was able to beat Cercyon with little effort at all. He was such a skilled warrior, that he slaughtered the first and second army of the Pallantides all by himself.
- Percy Jackson has some similarities to Theseus.
- In Ancient Athens, where citizens valued thought and intelligence far above physical strength, Theseus was believed to be the greatest Ancient Greek hero instead of Hercules.
- Although Theseus is a son of Poseidon, Athena's nemesis, he ironically inherited rule of Athens (Athena's city) from his stepfather, Aegeus. Today, despite being a tyrannical ruler and killing his son near the end of his reign, his legacy remains as he is remembered as Athens's greatest king. This could be viewed as a symbol of peace and the end of the feud between Athena and Poseidon.
- Theseus and Pirithous were the only mortals that ever attempted to capture Persephone from Hades.
- He was imprisoned in the Underworld and was later freed by Hercules around the same time as Jason met Medea. But Theseus encountered Medea early on in his life, and she had fled to Athens after giving up on Jason. This is currently still an unsolved timeline error.