Belgrade was a military fortification from the earliest ancient times. On the foundations of a Roman castrum, the Byzantines renewed the fort shortly after the Hunnic invasions, and according to historian Procopius, Iustinian himself contributed to its ”deserving” appearance. Still, during the restless times of the Middle Ages, it was demolished and rebuilt on multiple occasions, and in its unkempt condition it was given to Serbian Despot Stefan by Hungarian King Sigismund. According to his biographer, Bulgarian historian Constantine of Kostenets, the concern for renovating Belgrade remained undiminished throughout his reign.
Military infrastructure had received the most attention when it came to the renovations, so the city was surrounded by twofold walls and a deep ditch in the coastal area. The city had multiple entry points; a drawbridge and three gates (West, South and East). The eastern and southern gates had guard towers and were considered more important. There was also a Northern gate facing the lower town. The upper town covered the territory on the hill, whereas the lower town covered an area of plains towards river shores, but there is no information regarding the area of the modern city.
A focal point of the upper town was The Despot’s court, and in its immediate proximity was The Nebojša tower. It is an area in the vicinity of Defterdar’s Gate and the Mehmed Paša Sokolović’s drinking fountain. Another important location of the upper town was The Despot’s treasury, which was most likely located near the court.
The lower town was a large town settlement, with houses of merchants, craftsmen and citizens of Belgrade. There were many churches, but the most significant of those was The Church of Ascension. It is belived to have been located near Ružica Church nowadays.
Among other objects, a hospital and shelter for foreigners stand out as well.
The dock was on The Danube, on the northern part where The Nebojša Tower is located.
