Medea was compelled to flee; but a new danger awaited the hero from the fifty sons of Pallas, who had reckoned on succeeding their childless uncle Ægeus. Theseus, however, slew some in battle and expelled the rest.
He now undertook his greatest and most adventurous feat, in order to free his country from its shameful tribute to Minos, king of Crete, whose son, the youthful hero Androgeos, had been treacherously murdered by the Athenians and Megareans. Another account says that he was sent by Ægeus against the bull of Marathon, and thus slain. At any rate, Minos undertook a war of revenge. He first marched against Megara, of which Nisus, the brother of Ægeus, was king. Minos conquered him by means of his own daughter Scylla, who became enamoured of Minos, and cut off from her father’s head the purple lock on which his life depended. After having taken Megara and slain Nisus, Minos marched against Athens. Here he was equally successful, and compelled the vanquished Athenians to expiate the blood of his son by sending, every eight or (according to the Greek method of reckoning) every nine years, seven youths and seven maidens to be devoured by the Minotaur. This was a monster, half man and half bull. Twice already had the bloody tribute been sent, and the third fell just after Theseus’ arrival in Athens; he at once bravely offered to go among the allotted victims. He was resolved to do battle with the Minotaur, and to stake his life on the liberation of his country from the shameful tribute. Under the guidance of Aphrodite he passed over to Crete, and soon discovered the efficacy of her protection. The goddess kindled a passionate love for the hero in the breast of Ariadne, the daughter of Minos. Ariadne rendered him every possible assistance in his undertaking, and especially presented him with a clew of thread, by means of which Theseus, after having slain the Minotaur, was enabled to find his way out of the Labyrinth. We have already narrated how Ariadne was deserted by Theseus on the isle of Naxos, only to become the bride of Dionysus, the divine son of Semele. Theseus also landed at Delos, where he instituted the festival of the Delia in honour of the divine children of Leto. On reaching Athens, he showed his gratitude to his divine protectress by the institution of the worship of Aphrodite Pandemus. In honour of Dionysus and Ariadne, he instituted the Oschophoria, in which festival Athene also had a share. Lastly, in honour of Apollo, he instituted the Pyanepsia, a festival which was celebrated on the seventh day of the month Pyanepsion (end of October).
The happy return of Theseus from his Cretan expedition, however, proved the death of his aged father. Ægeus, as he stood on the coast looking for his son’s return, perceived that the ships had black sails instead of white, which were to have been hoisted in the event of his son’s success; and believing that all was lost, he cast himself headlong into the sea. This story was perhaps only invented to account for the name of the Ægean Sea.
With regard to the other exploits of Theseus, there exists the greatest variety of accounts as to the order in which they took place. As king, he is said to have been the first to unite the separate districts of Attica into one political community, with one state Prytaneum, and to have instituted the festival of the Panathenæa in commemoration of this event. The following, among his later exploits, are worthy of mention:—
1. He captured the bull of Marathon (said to have been the same which Heracles brought alive from Crete), and sacrificed it in Athens to Apollo Delphinius.
2. He assisted his friend Pirithoüs, the prince of the Lapithæ, in his contest with the Centaurs.
3. He undertook with Pirithoüs an expedition to Lacedæmon, in which they carried off Helen, the sister of the Dioscuri.
4. At the request of Pirithoüs, he accompanied him to the lower world to carry off Persephone; but Hades, enraged at their audacity, caused them both to be bound in chains and fastened to a rock. Theseus was rescued from this plight by Heracles, but during his absence the Dioscuri had released their sister from Aphidnæ, where she was confined.
5. He next joined Heracles in his expedition against the Amazons, and received, as the reward of victory, their queen Antiope, or Hippolyte. Another tradition asserts that Antiope followed him of her own free will to Athens, where she was married to him, and became the mother of Hippolytus, famed for his unhappy fate. His great beauty caused his step-mother Phædra, a later wife of Theseus, and a sister of Ariadne, to fall in love with him. As he withdrew himself from her dishonourable proposals by flight, she accused him to his father of attempts on her virtue. Theseus, in his wrath, besought Poseidon to punish his faithless son; and the god, who had sworn to grant any request of Theseus, sent a wild bull (i.e., a breaker) out of the sea as Hippolytus was driving in his chariot along the sea-shore. This so terrified his horses that Hippolytus was thrown from his chariot, and dragged along the ground till he was dead. This story—the scene of which was afterwards transferred to Trœzen, whither Theseus was supposed to have fled on account of a murder—was dealt with in a touching manner by the tragic poets. The Hippolytus of Euripides is still extant.
6. As a result of the carrying off of Antiope, a second contest with the Amazons was subsequently invented, in which Theseus was engaged alone, and which took place in the immediate neighbourhood of Athens. The Amazons are supposed to have invaded Attica, in order to release their queen. Antiope, however, was so enamoured of Theseus that she refused to return, and fought at her husband’s side, against her kindred, until she was slain.