Jewel of the present-day city, the Bastide is delimited by the boulevards laid out in the XVIIIth and XIXth centuries on the line of the old moat surrounding the formerly walled city. The military fortifications and its gates defended the lower city. The enclosing wall of the latter was built between 1355 and 1359 on the orders of the Count of Armagnac; its perimeter was 2,800 metres in length; the bastions were constructed at a later period, after 1359; at the time, military architects limited themselves to erecting round towers on the corners of the walls, with dimensions greater than those of the other sections of the wall.
Towards the end of the XVIth century, during the Wars of Religion which decimated the south of France, four bastions were erected on the corners of the walls: the Saint-Martial bastion in the north-west, the La Figuières bastion in the north-east, the Montmorency in the south-east and the Tour Grosse or Moulins bastion in the south-west (now known as the Calvary bastion).
On the eve of the 1789 Revolution, the lower city still had only four gates:
- the west gate, the Porte de Toulouse or the Porte des Augustins (rue de Verdun) adorned with two fine towers which made it a kind of small castle and which were restored in 1749, but following a decree signed by the Council and dated 31st May 1778 transferring to the lower city community authorities in perpetuity the walls, moat, towers, ramparts and rampart walk, the city consuls allowed the gate to fall into ruin and it was completely demolished in 1806.
- the north gate or the Porte des Carmes (end of the present-day rue Georges Clemenceau).
- the east gate or the Porte des Cordeliers, at the eastern end of the present-day rue Aimé Ramond (formerly the rue de la Mairie).
- the south gate or the Porte des Jacobins, now preserved and listed along with its surrounding area as a Historic Monument. The Porte des Cordeliers was in the early days of the city’s construction on the site of the gate of the former law courts at the eastern end of the rue Mage (now the rue de Verdun) and was moved in 1571 to the end of the rue de la Pellisserie (present-day rue Aimé Ramond).