The age of Theseus was the great era of those heroes, to whom the knights errant of the Gothic kingdoms afterwards bore a close resemblance. Hercules was his near kinsman. The actions of that extraordinary personage are reported to have been for some years the subject of universal conversation, and both an incentive and a direction to young Theseus in the road to fame. After having destroyed the most powerful and atrocious freebooters throughout Greece, Hercules, according to Plutarch, was gone into Asia; and those disturbers of civil order, whom his irresistible might and severe justice had driven to conceal themselves, took advantage of his absence to renew their violences. Being not obscure and vagabond thieves, but powerful chieftains, who openly defied law and government, the dangers to be expected from them were well known at Trœzen. Theseus however persevered in his resolution to go by land; alleging that it would be shameful, if, while Hercules was traversing earth and sea to repress the common disturbers of mankind, he should avoid those at his door, disgracing his reputed father by an ignominious flight over his own element, and carrying to his real father, for tokens, a bloodless weapon and sandals untrodden, instead of giving proofs of his high birth by actions worthy of it.
Proceeding in his journey he found every fastness occupied by men who, like many of the old barons of the Western European kingdoms, gave protection to their dependants, and disturbance to all beside within their reach, making booty of whatever they could master. His valour, however, and his good fortune procuring him the advantage in every contest carried him safe through all dangers; though he found nothing friendly till he arrived on the bank of the river Cephisus in the middle of Attica. Some people of the country meeting him there saluted him in the usual terms of friendship to strangers. Judging himself then past the perils of his journey, he requested to have the accustomed ceremony of purification from blood performed, that he might properly join in sacrifices and other religious rites. The courteous Atticans readily complied, and then entertained him at their houses. An ancient altar, said to have been erected in commemoration of this meeting, dedicated to Jupiter with the epithet of Meilichius, the friendly or kind, remained to the time of Pausanias.
When Theseus arrived at Athens, Ægeus, already approaching dotage, was governed by the Colchian princess Medea, so famous in poetry, who flying from Corinth had prevailed on him to afford her protection. Theseus, as an illustrious stranger invited to a feast, on drawing his hunting-knife, as it seems was usual, to carve the meat before him, was recognised by Ægeus. The old king immediately rising embraced him, acknowledged him before the company for his son, and afterward summoning an assembly of the people presented Theseus as their prince. The fame of exploits suited, as those of Theseus, to acquire popularity in that age had already prepossessed the people in his favour; strong marks of general satisfaction followed. But the party of the sons of Pallas was powerful: their disappointment was equally great and unexpected; and no hope remaining to accomplish their wishes by other means, they withdrew from the city, collected their adherents, and returned in arms. The tide of popular inclination, however, now ran so strongly in favour of Theseus that some even of their confidants gave way to it. A design to surprise the city was discovered; part of their troops were in consequence cut off, the rest dispersed; and the faction was completely quelled.
Quiet being thus restored to Athens, Theseus was diligent to increase the popularity he had acquired. Military fame was the means to which his active spirit chiefly inclined him; but, as the state had now no enemies, he exercised his valour in the destruction of wild beasts, and, it is said, added not a little to his reputation by delivering the country from a savage bull, which had done great mischief in the neighbourhood of Marathon.