Another early village was Sáseta on the Camino del Vino y el Pescado, the "road of wine and fish" that connected the Ebro valley to the Cantabrian coast.

In 1358 and 1417 Treviño joined the fraternities made up of several towns in the heartland and fringes of Álava, the core of the present-day province.

The first took place in 1646, led by the members and representatives of the local council backed up by 390 supportive signatures (households) from 44 spots all across the county, when the petition was turned down by the Crown of Castile and probably the count.

Two further attempts ensued for the re-incorporation to Álava before the Civil War, 1917–19 and 1936, both within the context of the works to design a Basque statute of autonomy.

A like referendum was held first time in 1940 just after the civil war, with a 98% of the voters supporting the same option, which nowadays is backed primarily, but not only, by Basque nationalists.

The Regional Council of Castile and León has opposed in modern times any such popular consultations on the matter or any binding effect of its results.

As can be seen from the numbers in the previous section, throughout most of the second half of the 20th century the population of Condado de Treviño declined steadily.

They are as follows:[5] In addition, the following hamlets have no formal status: Four sites within Condado de Treviño are formally recognized by the Spanish Ministry of Culture as part of Spain's Patrimonio Histórico (literally "historic patrimony", heritage sites): Other places of interest include the forests of Obécuri and Bajauri; Izki Natural Park, with the largest massing of Quercus pyrenaica in Europe; the gorge of the river Ayuda; the route from Sáseta to Oquina, crossing Laño-Laguardia; the Aguillo-Ajarte crossing of Palogán mountain; the town of Pariza; the town of Cucho, whose buildings have been completely restored; and the hermitages of San Formerio, San Vicentejo, Ermita de Albaina, and Ermita de Pariza.