The Beyazıt Meydanı draws its name from the Beyazıt Mosque, a central feature of the historic peninsula. In its earliest days, under Byzantine rule, the square was referred to as the 'Forum Tuari'. Following the conquest of Mehmed II, the area became associated with his palatial complex, which hosts Istanbul University today. Also associated with the old palatial complex was the Ağa Kapısı, the headquarters of the Janissaries. Remaining construction from this period includes the Old Barracks, former mint, and the Ministry of War building, which opens onto the Grand Bazaar constructed under Mahmud Paşa, the latter attesting to the han of the same name standing on the southwestern side of the square. Under Beyazıt II, the area was transformed with the addition of a külliye, and its subsequent services; the Beyazıt Mosque, madrasa, caravanserai, imaret kitchens, and hammam, at the start of the sixteenth century.
The square is connected to Topkapı Palace by the Divanyolu, the processional road connecting the old Palace to the grounds of Gülhane Park, upon which Topkapı is situated. In addition to being the sight of parades and commemorative practices, the square also maintained residential areas. Owing to its location between the ports and the trading center of the peninsula, the square has also supported a number of commercial industries.
Sources:
Yeşilkaya, Neşe. "From a Courtyard to a Square: transformation of the Beyazıt Meydanı in the early nineteenth century Istanbul," Middle East Technical University Journal of the Faculty of Architecture 24, no. 1 (2007): 71-92.