Its date of construction is unknown, though it is generally assumed to have been erected in Late Antiquity, perhaps in the 4th century during the reign of Constantine or Constantius. While the exact date of the Masonry Obelisk is uncertain, the reasons for setting it up in the Hippodrome are much clearer. An obelisk erected by Augustus in the Circus Maximus in 10 BC was among the first obelisks brought to Rome. Other obelisks, including the Vatican Obelisk, were also set up in other circuses over time. Once Constantinople became the new capital, there was a need for its emperors to emulate older Roman models. In addition, major imperial building projects once common in Rome began to be undertaken in Constantinople, as seen with the Forum of Constantine and the Hippodrome. Erecting an obelisk in Constantinople’s hippodrome directly recalled both the Circus Maximus and its obelisk erected by Augustus. This, in turn, linked Constantinople with the city of Rome, emphasizing the Romanitas (“Romanness”) of both the new capital and its emperors. 

The Masonry Obelisk also might share link with the Lateran Obelisk had erected in the Circus Maximus in 357. The fact that they have the same height does not seem to be a mere coincident. While Ammianus claims that Constantine had this obelisk brought to Alexandria from Thebes with the aim of moving it to Rome, its lost inscription, recorded when it was excavated in the 16th century, claims otherwise. It states that Constantine intended this obelisk to be sent to Constantinople.It could be argued that, as it was unable to be shipped in time for the dedication ceremony of Constantinople in 330, Constantine had the Masonry Obelisk built instead. Even if this is dismissed as unwarranted speculation, it is clear that both obelisks relate to the rivalry between Constantinople and Rome at the time. 
Obelisks came in fashion again in the 19th century, with Paris, London and New York acquiring their own Egyptian obelisks. Interesting, the Washington Monument, completed in 1884, was built in a similar fashion (with ashlar blocks) as the Masonry Obelisk. With a height of 169 meters, it was briefly the tallest structure in the world.