In the mid 19th-century, most of the rural estates in Gipuzkoa were farmed by tenants whose legal situation was passed from fathers to sons over the generations.
There was a paternal relationship between the landowners and their tenants. The rent was paid on a fixed date, normally the day of San Martín - although it was often put back until Santo Tomás. December 21.
All the owners that did not farm their own land, lived in the city. Many tenants, therefore, travelled to San Sebastián on that day with the money to pay the rent and a couple of capons. Sometimes, the owner would invite them to lunch.
The tenants took advantage of their trip to the capital to stock up with articles they could not find in the modest local stores and to sell their farmhouse produce. It was necessary to celebrate this event with a festival and therefore the fiesta of "Santo Tomás", was created, held in the Plaza de la Constitución of San Sebastián.