Sultanahmet Square, or the Hippodrome, was commisioned by Roman Emperor Septimius Severius at the end of 2nd century. Hippodrome was later hugely extended by Great Constantin. In the long, east side of this U-shaped hippodrome, there used to be an emperor lodge in the balcony where there were 4 bronze horses.
In the center, there used to be a shallow wall which divides the sand covered hippodrome field into two, around which cars raced, and over this wall there used to be monuments brought from many parts of the empire and statues of horses.The Hippodrome include the 3500-year-old Egyptian Obelisk of Theodosius, brought to Constantinople by Emperor Theodosius in 390 AD. You'll also see the spiral bronze base of a three-headed serpent sculpture brought from Delphi in Greece.During a visit in 1901, Kaiser Wilhelm II of Germany erected an elaborate temple-like fountain as a gift to the sultan and his people.