Isla Mayor is a municipality of important rice tradition that is located in the Marismas del Bajo Guadalquivir, partially occupying the Doñana Natural Park.
In ancient times, this land was covered by a lake to which the Romans gave the name of Lagus Ligustinus, which lost depth with the passing of time, causing it to turn into a marsh, which became a new source of resources for the surroundings of the area.
In 1253 King Alfonso X granted the Isla Mayor to the Council of Seville and in 1272 to the inhabitants of the Guard (which we now know as Puebla del Río). But the agricultural use of the area did not really begin until the twentieth century when, in 1926, the English company Islas del Guadalquivir SA, purchased the land from the Marquis of Casa Riera and began an important conditioning of the area for the creation of the first rice plantations, developing significant investments in infrastructures that favoured the establishment of numerous population centres; although this prosperity would not last long since the company would soon decide to abandon the project.
Later, in the middle of the Civil War, when General Queipo de Llano arrived to the island with the intention of starting the cultivation of rice once again, there was a new increase in population and it was renamed Villafranco del Guadalquivir, a name that would remain until 1994, when it became independent from Puebla del Río, and it was not until later, in 2000, that it took the name Isla Mayor.
Isla Mayor is therefore a population that, although established recently, has been closely linked to the cultivation of rice since ancient times, with this being the main source of wealth for the municipality and the socio-economic engine of the region.