The building above was constructed as a church between A.D. 532 and 537 by the Byzantine Emperor Justinian. This marked both architectural and engineering improvements. Hagia Sophia, also known as the Church of the Holy Wisdom, was originally constructed in the fourth century by Constantine the Great. Then later between 532 and 537 was rebuilt under the supervision of Justinian. This beautiful monument still stands today but is no longer used as a church but as a museum for all to see.