The Centaurs were a tribe of half-man and half-horse, living in Magnesia, a coastal region in Thessaly. The Centaur was depicted in arts to have a head, chest and arms of a man, while the rest of his body was that of a horse.

There were several different stories of their origin.

One version says that the Centaurs were said to be descendants of Centaurus, the son of Apollo and Stilbe, thus brother of Lapithus, who became descendants of the Thessalian tribe, known as the Lapiths (Λαπίθαι).

A more popular version say that this Centaurus was a son of Ixion, the king of Thessaly, and the the cloud, possibly named Nephele, who was created by Zeus, made to look like Hera. If Centaurus was the son of Ixion, then the Centaurs were very closely related to Peirithoüs.

In both version, Centaurus mated with the mares from Magnesia, southern Thessaly, which produced half-horse, half-man offspring. The Centaurs were also known as Hippocentaurs.

The Centaurs were known for their inability to drink alcohol. They become unruly when drunk. There were frequent clashes between the Lapiths and the Centaurs. The height of conflict was reached during the wedding of Peirithoüs & Hippodameia. Peirithoüs (Peirithous) was king of the Lapiths and friend of Theseus. Two of the Centaurs were prominent at the wedding, Eurytion and Nessus; Heracles would killed them later. With the help of some of Peirithoüs' guests, they were able to drive the Centaurs out of Thessaly. Most fled to Arcadia where they encountered Heracles, during his 4th Labour.

There were two friendly Centaurs to humans, Cheiron and Pholus.

The ancestor and eponym of the Centaurs.

Centaurus was usually said to be a son of Ixion and the phantom Hera, made out of cloud.

When Ixion tried to seduce or ravish the goddess Hera, her husband fashioned her look-alike from cloud. Zeus set the phantom Hera in the king's bed chamber, as a trap for Ixion. When Ixion had sex with the cloud, Zeus caaught him in the act, and sent Ixion to Tartarus,

According to Diodorus Siculus, Centaurus was a son of Apollo and the nymph Stilbe, who was a daughter of the river god Peneius and the naiad Creusa. Centaurus was also the brother of Lapithes, who was eponym of the Lapiths.

Centaurus mated with mares from the plains of Magnesia, in Thessaly, so that his children were cross-breed between humans and horses. The half-man, half-horse were called Centaurs.

The constellation Centaurus was probably him, but it was most likely the wise Centaur Cheiron.

Cheiron (Χείρων) was the most famous Centaur. Not only was Cheiron immortal, but he was one of the wisest beings on earth. Cheiron was the son of the Titan Cronus and Philyra, who was the daughter of Oceanus and Tethys.

Cronus had raped Philyra, while he was in the form of a stallion. When she gave birth to the Centaur, she was so ashamed that the gods had taken pity on her and had transformed her into a linden tree.

Cheiron had married Chariclo and they had several daughters – Endeis, Ocyrrhoe (Menalippe) and Theia. Endeis had married Aeacus, king of Aegina. This would make Peleus, his grandson, while Achilles would be his great-grandson.

Cheiron befriended many heroes, including Heracles and Peleus. Some heroes were even brought up by the wise Centaur, like Jason and Achilles. Cheiron taught these heroes how to hunt, and fight.

Cheiron was also a famous healer, who had taught Asclepius, son of Apollo, and later his Asclepius' two sons – Machaon and Podalirius, in the art of healing. He was also responsible for rearing and educating Aristaeüs, the agricultural god.

He even gave advice or prophecy to Apollo, in regarding to the heroine, Cyrene, foretelling how a city in Libya would be named after her. So even the god of prophecy listen to the wise Centaur.

His friendship with Heracles brought about his own death. As Heracles fought against the Centaurs during his fourth labour, the hero accidentally wounded his Centaur friend. Heracles' arrows were smeared with the venom of the monster Hydra. Cheiron had to live in great agony from the venom.

Later, during the eleventh labour, Heracles freed the Titan Prometheus from his chain; Cheiron found release from his torment. The gods allowed Cheiron to give up his immortality to Prometheus, to end his agony. The gods probably placed among the stars, as the constellation of the Centaurus.

A Centaur. Eurytion or Eurytus was one of the Centaurs involved in disrupting and fighting the Lapiths, at the wedding of Peirithous and Hippodameia. There were fighting for the land in Thessaly, particularly in the valley of the Peneius River.

An uneasy peace between the Lapiths and Centaurs existed before this wedding. The Centaurs shared the same ancestors with the Lapiths. According to Diodorus Siculus, Lapithus and Centaurus were brothers. But according to other sources, it was Peirithous who was half-brother of the Centaurs, and Ixion, king of the Lapiths were their father.

Being kins, Peirithous invited the Centaurs to the weddings. Peirithous had invited several other prominent figures, guests such Theseus, Peirithous' best friend; Peleus and young Nestor.

According to Ovid, it was the Centaur Eurytion who started disrupted wedding; he led other drunken Centaurs to abduct Hippodameia, the Lapith king's bride and other Lapith women. Fighting ensued. Theseus, Peleus and Nestor aided the king, and Caeneus, a Lapith chieftain, killed many Centaurs, before the Centaurs killed Caeneus. Eventually, the Lapiths drove out the Centaurs from the city and out of their kingdom. Many fled to Arcadia, including Eurytion. The Nessus fled to Aetolia.

A Centaur. Nessus was one of the Centaurs who fought against the Lapiths, at the wedding of Peirithous and Hippodameia. When the Lapiths drove out the Centaurs out of their kingdom, most fled to Mount Pholus at Aracadia. Nessus, instead, headed west to the Evenus River in Aetolia, where he acts as a ferryman.

Nessus encountered the hero Heracles, who was leaving Aetolia with his wife, Deïaneira. Nessus offered to ferry Deianeira across the Evenus. Heracles accepted and went ahead, but Nessus tried to rape Deianeira. Hearing his wife's cry for help, Heracles mortally wounded the Centaur.

Dying, Nessus instructed to keep his blood, which he falsely told the princess it was powerful love elixir. If Heracles was to stray from his marriage with her, she should smear his blood on the hero's shirt, and Heracles would love her again. Deianeira didn't know the poison that killed Nessus, came from the deadly venom of the Hydra. This blood would later killed Heracles.

See Deianeira and the Death of Heracles.

Pholus was one of the few Centaurs, who was friendly towards to mortals. Pholus was a friend of Heracles.

Pholus lived in a cave at Mount Pholus, which was named after him; this mountain was in Arcadia. He had wine that would drive other Centaurs crazy with it sweet smell.

One day, Heracles came to visit, during his 4th Labour, which was to fetch Erymanthian Boar. As his guest, Pholus opened the wine skin, but the smell of the wine drove many of the Centaurs mad with desire to drink this wine. Among those who attacked Heracles was the Centaur Eurytion. They attacked Heracles, but the hero killed many Centaurs with his poisoned arrows. Heracles managed to drive the Centaurs away, and Eurytion was among those who escaped. Eurytion would later meet Heracles again.

Pholus accidentally dropped one of Heracles' arrows on his hoof, and was killed instantly. Heracles buried Pholus.

Pholus wasn't the only one poisoned by the hero's arrow; Cheiron was helping Heracles. Heracles either accidentally shot him, or Cheiron dropped the arrow on his foot. However, Cheiron didn't die, being immortal, but he could not be cured. Later, Cheiron gave up his immortality, so he could finally die. See Cheiron.