Theseus’s story begins with the king of Athens, Aegeus, who was having trouble conceiving an heir. After consulting the oracle, he received a cryptic message that basically warned him not to sleep with a woman until he returned to Athens. For whatever reason, his friend Pittheus, king of Troezen, decided to sabotage this. He got Aegeus drunk and then sent his daughter Aethra to sleep with him. That same night, Poseidon also came down and seduced Aethra, and because of this, when Theseus was born, he was believed to have two biological fathers.
When Theseus was born, Aegeus essentially abandoned him to be raised by Aethra in Troezen, though he left behind a test where he placed a sword and sandals beneath a rock, telling Aethra that when Theseus was strong enough to lift the stone, he should take them and come to Athens.
When Theseus reaches the age of 16. He goes to lift the rock which he does with ease. He gets the sword and sandals and his mom tells him the truth about who is father(s) his. So Theseus goes out on a quest to Athens and claim his birthright.
Whilst on his quest, Theseus encounters a bunch of…unique personalities.
Periphetes, a bandit who is a son of Hephaestus, therefore he has a big club made of iron that he robs and murders people with. Theseus kills him with his own club and claims it as its own (like botw)
Sinis, a man so strong that he could single handedly bend down two pine trees that he would tie people two and then watch them get ripped apart by. Theseus did the same to him. He also hooked up with Sinis’s daughter. As you do.
Phaia, an old lady who had a giant pet known as the Cromyonium Sow that ate people. Theseus killed them both.
Sciron, a warlord who threw people into the sea where a giant turtle ate them. So Theseus pushed him off a cliff.
Cercyon, King of Eleusis who challenged any visitor of the city to wrestle with him to the death. So Theseus wrestles him to death.
Procrustes, a very weird guy who ran an inn where he would put guests on a bed, and if they were too small for it, he would stretch them out with a rack, or if they were too tall, he would cut off their limbs with a golden hammer. Theseus somehow got the dude to let his guard down, get him on the bed, and then cut off his limbs with his own hammer.
So after all these weird little mini bosses, Theseus finally reaches Athens. During the interlude of Theseus’s childhood, Aegeus remarried to Medea, so when Theseus arrived in Athens, Medea met with him before he could actually see his father and instantly knew he was Aegeus’s kid, which made her afraid that he may be a threat to her power, so she convinced him that the best way to prove himself worthy was to go fight the Marathonian Bull, a big fire breathing bull that was killing hundreds of people across the coast of the village of Marathon. Medea was expecting him to die but to her shock, Theseus survives the task and slays the bull.
When that plan failed, Medea thought of a new one where he convinced Aegeus that this stranger was trying to steal his throne and that the best way to get rid of him was to poison him during a banquet. But Theseus seems to have caught on to this, so right before Aegeus gave the drink, Theseus took out his sword revealing he was his long lost son all along. Aegeus was happy to finally be reunited with his son, and also a bit mad with Medea and sent her away.
Now that Theseus had accomplished his goal of meeting his father and becoming heir to the throne of Athens he had a few more side quests to do in the meantime.
His uncle Pallas (brother of Aegeus) was expecting to be king after Aegeus died due to his supposed lack of a son, and after Pallas died, the throne would pass to his 50 Sons. Since Theseus’s appearance kind of put a wrench in that plan, Pallas resorted to assassinating Aegeus and Theseus. However, Theseus was warned of the plan so he preemptively attacked them first, and killed Pallas and all 50 of his sons
He went on the Athenian road to the city of Delphi where he cleared it of all bandits and robbers. He also may have hooked up with a girl named Aegle. As you do.
In some versions, Theseus also went on the voyage to Colchis with Jason and the Argonauts. Don’t ask me how that makes any chronological sense, because it doesn’t!
By now, Theseus is doing pretty good as Prince of Athens, that is until he hears about the Minotaur.
Quick backstory. Sometime ago, King Minos of the Island nation of Crete, had pissed off Poseidon, who got revenge by making his wife Pasiphae, sleep with the Marathonian Bull (the same fire breathing bull previously mentioned) and that gives birth to the Minotaur. Skip a few years ahead, and at some point, Minos’s eldest son Androgeus was murdered by a couple of Athenians. Minos got revenge by invading Athens and forcing Aegeus to send over 14 Athenian teenagers to be eaten alive by the Minotaur, Which Minos locked up in the Labyrinth, a super complicated maze.
This goes on for a while until Theseus arrives and decides to do something about it. He personally volunteers to go to Crete and slay the Minotaur. His father makes him promise that if he survives, he is to replace the black sails that Theseus ship sails with and replace them with white sails. That way Aegeus could know he’s alive.
When the Athenians are shipped off to Crete, king Minos notices one of the Athenian girls, Eriboea, and tries to rape her…luckily Theseus comes to her rescue and basically threatens to beat Minos to death, and boast that he is quite capable of doing so since he’s a son of Poseidon. Minos and his punk ass challenges Theseus to prove his heritage by throwing a ring into the ocean for Theseus to bring back up. Luckily for Theseus, when he jumps in he realizes that he can now breathe underwater and a group of dolphins lead him to Poseidons’s kingdom, where he meets his wife, Amphitrite. She gifts Theseus back the golden ring, but also gives him a crown that can glow in the dark (this will be important later on).
Theseus receives extra help from Ariadne, the daughter of Minos, who took one look at him and instantly fell in love. She helps Theseus by giving him a thread that he can use to navigate his way out of the labyrinth. Theseus does just that, and he also uses his newly acquired glow in the dark crown to see where he’s going. He finally sees the Minotaur and kills it. Depending on who you ask, he uses his sword, his iron club, or he uses his own fist! Beowulf style!
After slaying the Minotaur and using the thread to navigate his way out of the labyrinth, he makes his escape with the other Athenians and Ariadne. Minos would have tried to stop them, but Theseus thought ahead and sabotaged all the other ships in the Cretan navy.
Whilst they were making their way back to Crete, Theseus and Ariadne took the time to celebrate by inventing a new style of dancing where they recreated the movements of labyrinth with the other Athenians. In some versions, Theseus also gives Ariadne his glowing crown as a wedding gift which later on becomes a constellation.
Now here’s where things get complicated. In some versions Athena orders Theseus to leave Ariadne because the god Dionysus wants her for himself. In others, Theseus abandons her because he’s a jerk so Dionysus comes to comfort Ariadne and then marry her. In others, Dionysus visits Theseus in his dreams and orders him to leave Ariadne or he’ll get murked, or in others Dionysus just straight up kidnaps Ariadne with no need for Theseus to leave.
So once Ariadne’s out of the way, Theseus is either so sad over losing her that he forgets to put on the white sail on the ship, so Aegeus thinks he’s dead when he sees it and hurls himself off a cliff…or Theseus was a dumbass who was too busy partying and that’s why he forgot to put on the life saving sail.
But either way, Aegeus is dead and Theseus is now king of Athens. He does a bunch of more stuff. Becomes best friends with a guy named Pirithous, exterminates all centaurs, meets Oedipus, bags the queen of the Amazons, talks Heracles out off offing himself, kills his son, goes on a downward spiral and starts kidnapping people and so much more. But that was the main gist of his early adventures.