Also known as Akademos, Hekademos or Hecademus was, an Attic hero, who, when Castor and Polydeuces [or Pollux] invaded Attica to liberate their sister Helen, revealed to them that she was hidden at Aphidnae. For this reason the Tyndarids [Castor and Pollux] always showed him much gratitude, and whenever the Lacedaemonians (Ancient Spartans) invaded Attica, they always spared the land belonging to Academus which lay on the Cephissus, six stadia from Athens. (Plut. Thes. 32; D. L. 3.1.9.).
This piece of land was subsequently adorned with olive plantations (Plut. Cim. 13), and was called Academia from its original owner.
Stories of Academus
Plutarch’s Lives, Thes. 32
Meanwhile Menestheus, the son of Peteos, grandson of Orneus, and great-grandson of Erechtheus, the first of men, as they say, to affect popularity and ingratiate himself with the multitude, stirred up and embittered the chief men in Athens. These had long been hostile to Theseus, and thought that he had robbed each one of the country nobles of his royal office, and then shut them all up in a single city, where he treated them as subjects and slaves.
The common people also he threw into commotion by his reproaches. They thought they had a vision of liberty, he said, but in reality they had been robbed of their native homes and religions in order that, in the place of many good kings of their own blood, they might look obediently to one master who was an immigrant and an alien.
While he was thus busying himself, the Tyndaridae [the twin helping gods Castor and Pollux, known also as Dioscuri] came up against the city, and the war greatly furthered his seditious schemes; indeed, some writers say outright that he persuaded the invaders to come.
At first, then, they [Castor and Pollux] did no harm, but simply demanded back their sister [Helen]. When, however, the people of the city replied that they neither had the girl nor knew where she had been left, they resorted to war.
But Academus, who had learned in some way or other of her concealment at Aphidnae, told them about it. For this reason he was honored during his life by the Tyndaridae, and often afterwards when the Lacedaemonians [Ancient Spartans] invaded Attica and laid waste all the country round about, they spared the Academy1 for the sake of Academus.
A different version comes from Dicaearchus, who says that Echedemus and Marathus of Arcadia were in the army of the Tyndaridae at that time, from the first of whom the present Academy was named Echedemia, and from the other, the township of Marathon, since in accordance with some oracle he voluntarily gave himself to be sacrificed in front of the line of battle.
To Aphidnae, then, they came, won a pitched battle, and stormed the town. Here they say that among others Alycus, the son of Sciron, who was at that time in the army of the Dioscuri, was slain, and that from him a place in Megara where he was buried is called Alycus. But Hereas writes that Alycus was slain at Aphidnae by Theseus himself, and cites in proof these verses about Alycus:
whom once in the plain of Aphidnae,
Where he was fighting, Theseus, ravisher of fair-haired Helen,
However, it is not likely that Theseus himself was present when both his mother and Aphidnae were captured.
1 A shady precinct near the river Cephissus, about a mile N.W. of Athens. Here Plato and his disciples taught. See Plut. Cim. 13.8.