Sonsierra

[2] The name Sonsierra derives from the term subserra, already mentioned by the monks of the monastery of San Millán de la Cogolla in the 12th century.

[3] For more than five centuries it formed a region within the merindad of Estella, of the ancient kingdom of Navarre that included the towns of San Vicente, Laguardia, Labraza, Viana and all their villages.

[3] The term "Subserra" also appears in the document that contains the confirmation of the Charter of Nájera that King Alfonso VI of Castile made in the year 1076.

Shortly after, during the civil wars of Navarre, a part of this principality fell into Castilian hands, never to return to the Pyrenean kingdom again.

[5] After the Castilian conquest and the last attempts of reconquest by the Navarrese monarch, from 1521 the region enjoyed a long period of peace, since the border was moved to the Pyrenees.

In some maps published on behalf of the Academy of San Fernando in Madrid, such as one drawn up by Tomás López in 1769, La Rioja appears.

In the northeastern part, it is shown as bordering the kingdom of Navarre, since it remained as such, under the Hispanic Monarchy, governed by a viceroy until 1841, when it was considered just another province.

It should also be noted that the aforementioned map of Tomás López was criticized by illustrious people of the time for having several inaccuracies, such as not including some parts of the region of La Rioja.

[12] However, the proposed division of the Spanish State remained without effect due to the absolutist reaction of Ferdinand VII and the situation returned to the previous one.