The fastened enclosure surrounding the town, which made of Brasov one of the most reinforced medieval towns in Transylvania, has been developed in phases, between the XIVth and the XVIIth centuries. King Louis I of Anjou (1342-1382) granted the inhabitants of Brasov the privilege to built stone fortifications, a privilege renewed by Sigismund of Luxembourg (1387-1437), came to Brasov in 1395, in order to conclude the anti-ottoman alliance treaty with Mircea cel Bătrân (Mircea the Old), where he comes back in 1397-1398 and later in 1427, to supervise the defence works. The construction of the Goldsmiths’ Bastion in 1646 (dismantled in the XIXth century along with the entire north-eastern side of the assembly), completed the works undertaken at the defence system of the town, carried on during three centuries.
From the stronghold which perimeter occupied an irregular quadrilateral plan, endowed initially with several walls, zwingers, dried or water ditches, ponds eastwards and westwards, 27/28 defence towers and eight bastions maintained and defended by the artisans corporations, among the best conserved nowadays there are the Lower Walls’ fortifications, located across the Graft canal and the Upper Walls, under Tâmpa hill.  The defence system of the stronghold used to be endowed by four external watch towers:  on the northern side, the Black Tower (the end of the XIVth century) and the White Tower (1460/1494), the latter connected to the town’s fortifications through Graft Bastion, which used to serve as bridge over the rivulet streaming on the foot of Romurilor hill. The other two towers on mount Tâmpa versant towards the town, at the level of the Weavers Bastion and the Drapers Bastion are nowadays conserved only at archaeological level. 
The main entrances in the „Stronghold”, at the level of the three suburbs, „The Old Brasov” (northwards), Blumăna” (eastwards) and „Șchei” (westwards), used to be protected by monumental constructions encompassing towers, bastion and folding bridges over the water ditches.  Between 1522 and 1532, the most important accesses from the north-eastern side of Brasov have been largely extended: Porta Porzel and Porta Petri, the latter subsequently called the Monastery Gate and later the Custom Gate.
In 1559 is erected the tower of Ecaterina Gate towards Șcheii Brașovului neighbourhood, the only witness of the ancient fortifications of this side of the town.