Although the Hippodrome is usually associated with Constantinople's days of glory as an imperial capital, it actually predates that era. The first Hippodrome was built when the city was called Byzantium, and was a provincial town of moderate importance. In AD 203 the Emperor Septimius Severus rebuilt the city and expanded its walls, endowing it with a hippodrome, an arena for chariot races and other entertainment.
In AD 324, the Emperor Constantine the Great decided to move the seat of the government from Rome to Byzantium, which he renamed Nova Roma (New Rome). This name failed to impress and the city soon became known as Constantinople, the City of Constantine. Constantine greatly enlarged the city, and one of his major undertakings was the renovation of the Hippodrome. It is estimated that the Hippodrome of Constantine was about 450 m long and 130 m wide. Its stands were capable of holding 100,000 spectators.
The race-track at the Hippodrome was U-shaped, and the Kathisma (emperor's loge) was located at the eastern end of the track. The Kathisma could be accessed directly from the Great Palace through a passage which only the emperor or other members of the imperial family could use. The Hippodrome Boxes, which had four statues of horses in gilded copper on top, stood at the northern end; and theSphendone (curved tribune of the U-shaped structure, the lower part of which still survives) stood at the southern end. These four gilded horses, now called the Horses of Saint Mark, whose exact Greek or Roman ancestry has never been determined, were looted during the Fourth Crusade in 1204 and installed on the façade of St Mark's Basilica in Venice. The track was lined with other bronze statues of famous horses and chariot drivers, none of which survive. The hippodrome was filled with statues of gods, emperors and heroes, among them some famous works, such as a Heracles by Lysippos, Romulus and Remus with their wolf and the Serpent Columnof the Plataean tripod. In his book De Ceremoniis (book II,15, 589), the emperor Constantine Porphyrogenitus described the decorations in the hippodrome at the occasion of the visit of Saracen or Arab visitors, mentioning the purple hangings and rare tapestries.
Throughout the Byzantine period, the Hippodrome was the centre of the city's social life. Huge amounts were bet on chariot races, and initially four teams took part in these races, each one financially sponsored and supported by a different political party (Deme) within the Roman/Byzantine Senate: The Blues (Venetoi), the Greens (Prasinoi), the Reds (Rousioi) and the Whites (Leukoi). The Reds (Rousioi) and the Whites (Leukoi) gradually weakened and were absorbed by the other two major factions (the Blues and Greens).
A total of up to eight chariots (two chariots per team), powered by four horses each, competed on the racing track of the Hippodrome. These races were not simple sporting events, but also provided some of the rare occasions in which the Emperor and the common citizens could come together in a single venue. Political discussions were often made at the Hippodrome, which could be directly accessed by the Emperor through a passage that connected the Kathisma (Emperor's Loge at the eastern tribune) with the Great Palace of Constantinople.
The rivalry between the Blues and Greens often became mingled with political or religious rivalries, and sometimes riots, which amounted to civil wars that broke out in the city between them. The most severe of these was the Nika riots of 532, in which an estimated 30,000 people were killed and many important buildings, such as the second Aya Sophia Church, were destroyed. The current (third) Aya Sophia was built by Justinian following the Nika Revolt.
Constantinople never really recovered from its sack during the Fourth Crusade and even though the Byzantine Empire survived until 1453, by that time, the Hippodrome had fallen into ruin. The Ottoman Turks, who captured the city in 1453 and made it the capital of the Ottoman Empire, were not interested in racing and the Hippodrome was gradually forgotten, although the site was never actually built over.
The Hippodrome was used for various occasions such as the lavish and days-long circumcision ceremony of the sons of Sultan Ahmed III. In Ottoman miniature paintings, the Hippodrome is shown with the seats and monuments still intact. Although the structures do not exist anymore, today's Sultanahmet Square largely follows the ground plan and dimensions of the now vanished Hippodrome.
The Magical Column in the Horse Square
As to the legend, a philosopher called “Surende” in time of the King Pozantin had made a three-headed bronze dragon sculpture in the Horse Square to remove the venomous animals like snake, scorpion, gobo and centipede. And none venomous and scary animal had been living in Istanbul city. This dragon sculpture was a magical wreathed column ten yards high. This column having another part of ten yards had stayed under the ground when the Blue Mosque had been built.
It is said that Selim the Sot had broken the dragon’s jaw on its head facing the west with his mace when he had been passing under the statue. After the dragon’s jaw had been broken, it was believed that the snakes came out in the west and spread in Istanbul. It had been thought that if the other head had been damaged, Istanbul would have been filled with the snakes, centipedes.