Presently located within the walled district of Fatih, the humongous cistern design is estimated to be from the period of Emperor Theodosius II’s reign, during the first-half of 5th century AD. Theodosius II is known for the magnificent Theodosian Walls of Constantinople, and it was under his patronage that this huge undertaking was started by then-praefectus urbi of Constantinople, Aetius. In fact, most historians pinpoint the actual date of construction to be in the year 421 AD.
In terms of orientation, the Cistern of Aetius was designed in a parallel manner to the main thoroughfare of the super-city (also known as Mese), while it was supplied by water from the Valens Aqueduct, a gargantuan 971 m (3,200 ft) long Roman water-carrying system built in the late 4th century AD. As we mentioned before, the Cistern of Aetius itself was very large – so much so that it was used a reference point for recognizing other eminent buildings in the vicinity. To that end, the 290,360 cu m structure had a capacity of holding 66–79 million US gallons of water with parameter walls as thick as 5.20 m (17.1 ft).
Many experts believe the Cistern of Aetius exhibits opus listatum, an intricate Roman method of construction that entailed alternating layers of bricks and stones. As for the purpose of the herculean effort, there are hypotheses that relate to the cistern being used to supply water to the moats beyond the huge city walls. In any case, the reservoir went dry by at least early 16th century, as evidenced from the accounts of famous French topographer Pierre Gilles. And finally after almost 300 years, the engineering marvel was ‘practically’ transformed into a large sports ground (in 1928) by the newly established government of Republic of Turkey.