In Greek mythology, the Taraxippus (plural: taraxippoi, "horse disturber", Latin equorum conturbator  ) was a presence, variously identified as a ghost or dangerous site, blamed for frightening horses at hippodromes throughout Greece.  Some taraxippoi were associated with the Greek hero cults or with Poseidon in his aspect as a god of horses (Ancient Greek : Ποσειδῶν ῐ̔́πποs) who brought about the death of Hippolytus.  Pausanias, the ancient source offering the greatest number of explanations, regards it as an epithet rather than a single entity. 
The most notorious  of the taraxippoi was the Taraxippos Olympios at Olympia. Pausanias describes the site:
The race-course [of Olympia] has one side longer than the other, and on the longer side, which is a bank, there stands, at the passage through the bank, Taraxippos, the terror of the horses. It is in the shape of a round altar and there the horses are seized by a strong and sudden fear for no apparent reason, and from the fear comes a disturbance. The chariots generally crash and the charioteers are injured. Therefore the drivers offer sacrifices and pray to Taraxippos to be propitious to them. 
Horse- and chariot-races were a part of funeral games from the Homeric era. The use of a hero's tomb or an altar as the turning-post of a racetrack originates in rituals for the dead.  In the Iliad, Achilles kills Hector in retribution for the death of his friend Patroclus, then drives his chariot around the funeral pyre three times, dragging the Trojan prince's body. This magical encircling may originally have been a binding propitiation of the dead, to assure their successful passage into the afterlife and keep them from returning. 
The horse had been established as a funerary animal by the Archaic era. Commemorative art in Greece, the Etruscan civilization and ancient Rome often depicts a chariot scene or the deceased riding a horse into the afterlife.  The design of the turning posts (metae) on a Roman race course was derived from Etruscan funeral monuments, and the far turn of the Circus Maximus skirted an underground altar used for the Consualia festival at which "Equestrian Neptune" (the Roman equivalent of Poseidon Hippos, Ποσειδῶν ῐ̔́πποs) was honored.  The turn of a racetrack is the most likely spot for a crash, and so the natural dangers of a sharp curve combined with the sacral aura of a tomb or other religious site led to a belief in a supernatural presence.  Race horses were often adorned with good-luck charms or amulets to ward off malevolence. 
Some said the source of terror at Olympia was the ghost of Oenomaus, harming chariot racers as he had harmed suitors of Hippodamia. Others say it was a tomb of Myrtilus, who caused the death of Oenomaus.  Others said it was the tomb of an Earth-born giant, Ischenus. 
At the Isthmian Games, the Taraxippos Isthmios was the ghost of Glaucus of Pontiae, who was torn apart by his own horses.  The Taraxippos Nemeios caused horses to panic during the Nemean Games: "At Nemea of the Argives there was no hero who harmed the horses, but above the turning-point of the chariots rose a rock, red in color, and the flash from it terrified the horses, just as though it had been fire." 
The comic playwright Aristophanes makes a joke in The Knights calling Cleon Taraxippostratus, "Disturber of the Horse Troops." 
Poseidon was one of the Twelve Olympians in ancient Greek religion and mythology, presiding over the sea, storms, earthquakes and horses. He was the protector of seafarers and the guardian of many Hellenic cities and colonies. In pre-Olympian Bronze Age Greece, Poseidon was venerated as a chief deity at Pylos and Thebes, with the cult title "earth shaker"; in the myths of isolated Arcadia, he is related to Demeter and Persephone and was venerated as a horse, and as a god of the waters. Poseidon maintained both associations among most Greeks: He was regarded as the tamer or father of horses, who, with a strike of his trident, created springs. His Roman equivalent is Neptune.
Triton is a Greek god of the sea, the son of Poseidon and Amphitrite, god and goddess of the sea respectively. Triton lived with his parents in a golden palace on the bottom of the sea. Later he is often depicted as having a conch shell he would blow like a trumpet.
Alope was in Greek mythology a mortal woman, the daughter of Cercyon, known for her great beauty.
Ageladas or Hagelaedas was a celebrated Greek (Argive) sculptor, who flourished in the latter part of the 6th and the early part of the 5th century BC.
In Greek mythology, Pelops was king of Pisa in the Peloponnesus region. He was the son of Tantalus and the father of Atreus.
Hippodamia was a Greek mythological figure. She was the queen of Pisa as the wife of Pelops.
In Greek mythology, King Oenomaus of Pisa, was the father of Hippodamia and the son of Ares. His name Oinomaos denotes a wine man.
Neptune is the Roman god of freshwater and the sea in Roman religion. He is the counterpart of the Greek god Poseidon. In the Greek tradition, he is a brother of Zeus and Hades; the brothers preside over the realms of heaven, the earthly world, and the seas. Salacia is his wife.
Chariot racing was one of the most popular ancient Greek, Roman, and Byzantine sports. In Greece, chariot racing played an essential role in aristocratic funeral games from a very early time. With the institution of formal races and permanent racetracks, chariot racing was adopted by many Greek states and their religious festivals. Horses and chariots were very costly. Their ownership was a preserve of the wealthiest aristocrats, whose reputations and status benefitted from offering such extravagant, exciting displays. Their successes could be further broadcast and celebrated through commissioned odes and other poetry.
The hippocampus or hippocamp, also hippokampos, often called a sea-horse in English, is a mythological creature shared by Phoenician, Etruscan, Pictish, Roman and Greek mythology, though its name has a Greek origin. The hippocampus has typically been depicted as having the upper body of a horse with the lower body of a fish.
The ancient Olympic Games were a series of athletic competitions among representatives of city-states and were one of the Panhellenic Games of Ancient Greece. They were held in honor of Zeus, and the Greeks gave them a mythological origin. The originating Olympic Games are traditionally dated to 776 BC. The games were held every four years, or Olympiad, which became a unit of time in historical chronologies. They continued to be celebrated when Greece came under Roman rule in the 2nd century BC. Their last recorded celebration was in AD 393, under the emperor Theodosius I, but archeological evidence indicates that some games were still held after this date. The games likely came to an end under Theodosius II, possibly in connection with a fire that burned down the temple of the Olympian Zeus during his reign.
In Greek and Roman mythology, Glaucus, usually surnamed as Potnieus, was a son of Sisyphus whose main myth involved his violent death as the result of his horsemanship. He was the king of the Boeotian city of Potniae or sometimes of Corinth. Glaucus was the subject of a lost tragedy by Aeschylus, Glaucus Potnieus(Glaucus at Potniae), fragments of which are contained in an Oxyrhynchus Papyrus.
The Trigarium was an equestrian training ground in the northwest corner of the Campus Martius in ancient Rome. Its name was taken from the triga, a three-horse chariot.
The biga is the two-horse chariot as used in ancient Rome for sport, transportation, and ceremonies. Other animals may replace horses in art and occasionally for actual ceremonies. The term biga is also used by modern scholars for the similar chariots of other Indo-European cultures, particularly the two-horse chariot of the ancient Greeks and Celts. The driver of a biga is a bigarius.
The di inferi or dii inferi were a shadowy collective of ancient Roman deities associated with death and the underworld. The epithet inferi is also given to the mysterious Manes, a collective of ancestral spirits. The most likely origin of the word Manes is from manus or manis, meaning "good" or "kindly," which was a euphemistic way to speak of the inferi so as to avert their potential to harm or cause fear.
In ancient Roman religion, the October Horse was an animal sacrifice to Mars carried out on October 15, coinciding with the end of the agricultural and military campaigning season. The rite took place during one of three horse-racing festivals held in honor of Mars, the others being the two Equirria on February 27 and March 14.
In the topography of ancient Rome, the Tarentum or Terentum was a religious precinct north of the Trigarium, a field for equestrian exercise, in the Campus Martius. The archaeological survey of the site shows that it had no buildings.
The Greek lyric poet Pindar composed odes to celebrate victories at all four Panhellenic Games. Of his fourteen Olympian Odes, glorifying victors at the Ancient Olympic Games, the First was positioned at the beginning of the collection by Aristophanes of Byzantium since it included praise for the games as well as of Pelops, who first competed at Elis. It was the most quoted in antiquity and was hailed as the "best of all the odes" by Lucian. Pindar composed the epinikion in honour of his then patron Hieron I, tyrant of Syracuse, whose horse Pherenikos and its jockey were victorious in the single horse race in 476 BC.
The Hippodrome of Olympia housed the equestrian contests of the Ancient Olympic Games. According to Pausanias, it was situated to the south of the Stadium and covered a large area about 600 meters long and 200 meters wide. The hippodrome was a wide, flat, open space where the starting point and the finish line were designated with a pole and a second smaller pole called nyssa designated the turning point.
The Eastern pediment of the Temple of Zeus at Olympia depicts the tale of Pelops just before the chariot race wherein he kills the king Oenomaus in order to win the hand of his daughter Hippodamia. The depiction of this chariot race on the east pediment of the Temple of Zeus at Olympia, along with that of the Twelve Labours of Heracles on the metopes of the frieze, relate to the location of the temple in Olympia; the chariot race and Heracles were both believed to have started the tradition of the Olympic Games.