[5] Some of the first bastides were built under Raymond VII of Toulouse to replace villages destroyed in the Albigensian Crusade.
[6] Bastides were developed in number under the terms of the Treaty of Paris (1229), which permitted Raymond VII of Toulouse to build new towns in his shattered domains but not to fortify them.
The new inhabitants were encouraged to cultivate the land around the bastide, which, in turn, attracted trade in the form of merchants and markets.
Responsibilities and benefits were carefully framed in a charter, which delineated the franchises ('liberties') and coutumes ('customs') of the bastide.
[5] Most bastides were developed with a grid layout of intersecting streets, with wide thoroughfares that divide the town plan into insulae, or blocks, through which a narrow lane often runs.
[9] They included a central market square surrounded by arcades (couverts) through which the axes of thoroughfares passed, with a covered weighing and measuring area.
[10] The Roman model, the castrum with its grid plan and central forum, was inescapable in a region since Roman planning precedents survived in medieval cities such as Béziers, Narbonne, Toulouse, Orange and Arles.
This varied between ten and several thousand (3,000 in Grenade-sur-Garonne) The streets were usually 6–10 m (20–33 ft) wide, so a chariot could pass through.
Fortifications were added later and were paid for through a special tax or carried out through a law that required the people of the city to help build the walls.
[citation needed] At the beginning of the Hundred Years' War, many bastides that had no city walls were destroyed.
The bastides' forms resulted from "the friction engendered by interaction, expedience, pragmatism, legal compromise, and profit," Adrian Randolph observed in 1995.
[14] Most bastides were built in the Lot-et-Garonne, Dordogne, Gers and Haute-Garonne départements of France, because of the altitude and quality of the soil.
The best-known today are probably Andorra la Vella and Carcassonne, but the most populated is Villeneuve-sur-Lot, the 'new town on the River Lot'.