In the 1930s, the famous Majorcan smuggler and landowner, Juan March, bought the latifundios to the Larios family and divided them into plots, putting them up for sale to farmers in other areas of Andalusia and Valencia.

The presence of settlers from Jimena and other municipalities in the Campo de Gibraltar was scarce, it seems, due to the misgivings that this landowner produced in the region.

[4] Although San Martín del Tesorillo was declared an agricultural colony in 1879, its consolidation as a population center began in the 1930s after its division into parcels and the arrival of settlers.

The recognition of municipal autonomy and its jurisdictional term, of 4857 hectares, was approved by Decree of the Junta de Andalucía on 24 April 1999 under the figure of an Autonomous Local Entity.

[5] In 2018, San Martín del Tesorillo was separated from the city council of Jimena de la Frontera and since October 3 of that year is officially a new municipality.