The first reference to the tortilla in Spanish is found in a Navarrese document, as an anonymous "mousehole memorial" addressed to the court of Navarre in 1817.

Although it remains unknown whether this is true, it appears the tortilla started to spread during the early Carlist Wars.

[5] Another tale is that the recipe was learnt by Spanish prisoners captured after the Battle of Montes Claros during the Portuguese Restoration War in 1665.

[6] After the Portuguese victory, more than 6,000 Spanish soldiers were kept in captivity for three years until the 1668 Treaty of Lisbon was signed.

Upon their release, these prisoners brought part of the culture of Alentejo to Spain, including many recipes, which featured a potato egg pie that evolved into the modern version of "tortilla".

Traditionally, the inhabitants of each town go to a nearby rural area where they spend the day among family members and friends, eating Spanish tortillas and other foods, and playing games.