As early as the fifth-century, the Psalmody Abbey was founded in the region and one of the few settlements still in existence at the time of Louis' interest in the area. The monks inhabiting the abbey had been disperesed by successive attacks by Muslims until the eleventh-century, when the abbey was reunited.
The monks then found themselves in great debt in the thirteenth-century and, as a result, Louis had little trouble obtaining the land he wanted for the development of the town.
Louis was interested in the founding a city in the area because of its marshes and lagoons, which could protect the city from major overland invasions or major attacks from sea. In 1266 Louis first came up with the plan to build the massive walls that surround the heart of the medieval village and still stand today.
At the end of the thirteenth-century the city had reached a population of 12,000 inhabitants, twice that of today. Eventually, the receding seas brought about the economic decline of the city.
For students of medieval history, a trip to the city is well worth the effort, as it is so well preserved and maintains its medieval charm. One can see herds of bulls and horses that live in a semi-wild state on salty plains surrounding Aigues-Mortes.
The La Gardette Gate, Notre-Dame des Sablons Church, and the Tower of Constance are especially worth seeing, as they are among the more interesting and well preserved medieval structures of the city.