I have already written quite a lot about the Hellenic hero Hēraklēs, whose name was later Romanized as 'Hercules'. In fact, I am writing a continuing series about his labours. That said, this post will not be just about him, because there were others associated with the myth, despite the name.

The name of the constellation in ancient Hellas was Ἐγγόνασιν, The Kneeler, or On His Knees. That said, the ancient Hllenes already associated the myth with the hero Hēraklēs. Hyginus, for example, in his 'Atronomica' describes:

"Eratosthenes says he is Hercules, placed above the dragon we have already mentioned, and prepared to fight, with his left hand holding his lion skin, and his right the club. He is trying to kill the dragon of the Hesperides, which, it is thought, never was overcome by sleep or closed its eyes, thus offering more proof it was placed there as a guard. Panyassis in the Heraclea says of the sign that Jupiter, in admiration of their struggle, placed it among the stars; for the dragon has its head erect, and Hercules, resting on his right knee, tires to crush the right side of its head with his left foot. His right hand is up and striking, his left extended with the lion skin, and he appears to be fighting with all his strength.

Aeschylus, in the play entitled Prometheus lyomenos, says that he is Hercules, fighting not with the dragon, but with the Ligurians. For he says that at the time Hercules was driving away the cattle of Geryon, he journeyed through the territory of the Ligurians. They joined forces in trying to take the herd from him, and pierced many of the beasts with arrows. But after Hercules’ weapons failed, worn out by the number of the barbarians and lack of arms, he fell to his knees, already suffering from many wounds. Jove, however, out of pity for his son, provided that there should be a great supply of stones around him. With these Hercules defended himself and put the enemy to flight. And so Jove [Zeus] put [t]he image of his fighting form among the constellations." [II.6]

Yet, Hyginus also mentions other possibilities and other noteworthy people who have an opinion on the matter; Araethus, for example, who calls this figure Ceteus, son of Lycaon, and father of Megisto:

"He seems to be lamenting the change of his daughter to bear form, kneeling on one knee, and holding up outstretched hands to heaven, asking for the gods to restore her to him." [II.2]

For those who these names are unfamiliar, Megisto is in some writers another form for Kallistô, the mother of Arcas, who is also called Themisto. I have discussed the happenings with this family before, for the constellation Boötes, but will recap for the unity of this post. Arcas (Ἀρκάς), son of Zeus and Kallistô (Καλλιστω). After Arcas was born, Hera caught wind of the affair and turned Kallistô into a bear. Alternatively, Kallistô was a priestess of Artemis, and Artemis punished her for losing her virginity by turning her into a bear. Because of the metamorphosis, the boy was raised by his maternal grandfather Lycaon, who would later kill and serve up his grandson to the Theoi as dinner, for which he was turned into a (were)wolf. When Arcas grew up, he went out to hunt and found a beautiful bear. He chased her through the woods. The bear--his transformed mother Kallistô--ran towards him as soon as she recognized her son. Arcas was terrified and raised his bow to shoot her. Zeus intervened swiftly and placed Kallistô and her son in the sky. Kallistô became Ursa Major and Arcas either Ursa Minor or Boötes.

Hyginus goes on to quote Hegesianax, who says that:

"...he is Theseus, who seems to be lifting the stone at Troezene. Aegeus is thought to have put [corrupt] and a sword under it, and warned Aethra, the mother, not to send him to Athens until he could lift the stone by his own strength and bring the sword to his father. And so he seems to try to lift the stone as high as he can. In this connection, too, some have said that the Lyre, placed nearest this sign, is the lyre of Theseus, for he was skillful in all the arts and seems to have learned the lyre as well. This, too, Anacreon says: Near Theseus, son of Aegeus, is the Lyre." [II.6]

Theseus was fathered by Aegeus and Poseidon, whom had both slept with his mother Aethra, and was thus destined to become a hero. In order to claim his rightful place as ruler over Athens, he had to uncover his father's sandals and sword from under a stone in his mother's birth land where Theseus grew up, and bring it to his mortal father. Theseus lifting the stone at Troezene would have been his first heroic act, and thus worthy of immortalization in the stars.

Hyginus offers a few more options:

"Others call him Thamyris, blinded by the Muses, kneeling as a suppliant; others, Orpheus, killed by the Thacian women because he looked on the rites of Father Liber. Again, some have said that he is Ixion with his arms bound, because he tried to attack Juno. Others say he is Prometheus, bound on Mt. Caucasus." [II.6]
I have written about the affairs with Ixion and Prometheus, so for reference, please visit those posts. I have also written about Orpheus, but with a different constellation: Cygnus: the swan. In it I describe how Orpheus wanders the world after loosing his wife for good, and stumbles upon revelers who rip him apart. His lyre is placed into the sky and Plato describes that Orpheus is turned into the constellation Cygnus because he does not want to be reincarnated as a woman, a risk he would run if he stayed in human form. It seems others thought he was put into the sky as a man regardless, and near his lyre at that.

Thamyris  (Θάμυρις) is new to this blog. He was the son of Philammon and the nymph Argiope, and a Thracian singer who was so proud of his skill that he boasted he could outsing the Muses. He competed against them and lost. As punishment for his presumption they blinded him, and took away his ability to make poetry and to play the lyre. Hómēros outlines the tale in the Iliad:

"From Pylos, and lovely Arene; from the ford of the Alpheius at Thryum, from well-built Aepy, from Cyparisseis, and Amphigeneia, Pteleos, Helos, and Dorium, where Thamyris the Thracian met the Muses, as he came from Eurytus’ house in Oechalia, and they put an end to all his singing: he who had boasted he would win his contest with those aegis-bearing daughters of Zeus, they blinding him in anger, robbing him of his sweet gift of song, so he forgot the cunning of his harp; in their fleet of ninety hollow ships the warriors came, led by Nestor the Gerenian charioteer." [II: 581-644]

It seems there is great variety in the interpretation of the person the constellation depicts, but whomever it is, they are visible at latitudes between +90° and −50°, and best visible at 21:00 (9 p.m.) during the month of July.