[en] The aim of this paper is to highlight one of the most prominent viscountcies of Gascon territories during the Middle Ages, which controlled a territory stretching from the Gascon coast to the central lands of the Landes, but it also extended its domain to a part of Basse-Navarre territories. These latter would have been of fundamental interest because they would open the door to a framework of alliances forged within the lands under the rule of the king of Navarre. Through this article we will point out the strategies of these viscounts to increase their assets around the core of their domain of Tartas, and also the social networks that they built up all throughout the Middle Ages, which allowed them to go beyond the strict spatial scale of their domains. This will enable us to see how the Viscounts of Tartas, which originally were merely a secondary entity in the Gascon territories, gradually became prominent figures not only within the lands of the king of England, but also for the king of Navarre, who was at that time trying to assert his control over the region of Basse Navarre, relying on the local aristocracy. However, we will see that the relationship with the King of Navarre was subsidiary to the territorial strategies of the viscounts, as their interests were concentrated in the central lands of the Landes or the basin of the Garonne river, in the Bordeaux area. Their social networks, by contrast, were carefully designed considering Navarrese territories, which would enable them to establish long-term partnerships with important families such as the Viscounts of Béarn. The wish of the viscount of Tartas to organize the territory as well as to build a strong network within the Gascon territory was truncated by the biological extinction of the main branch of the family in 1312, although their strategies settled a framework which allowed their heirs - the lords of Albret - to become one of the most powerful entities of Gascony in the Middle Ages.

[es] El objeto de este trabajo es poner en valor uno de los vizcondados más destacados en el espacio del otro lado de los Pirineos durante la Edad Media, que controlaba un territorio que abarcaba desde la costa gascona hasta la Landa central, aunque también extendió su dominio a una parte de los territorios de Ultrapuertos. Estos últimos revestían un interés fundamental, ya que le abrirían las puertas a un marco de alianzas tejidas con las tierras bajo el dominio de los reyes de Navarra. De este modo, a lo largo de este artículo se van a seguir sus estrategias de control y aumento del patrimonio alrededor de su núcleo patrimonial de Tartas, y también las redes sociales que fueron estructurando a lo largo del tiempo, que les permitían sobrepasar la escala espacial de sus dominios. Esto nos permitirá observar cómo progresivamente la figura de los vizcondes de Tartas, que en un principio constituía otra entidad secundaria entre las que sembraban el territorio gascón, se configu- raron como personajes importantes dentro de las tierras dominadas por el rey de Inglaterra, aunque también lo serían para el rey de Navarra, que en este momento intentaba afirmar su control sobre las tierras ultraportanas, apoyándose en la aristocracia local. Sin embargo, veremos que la relación con el monarca navarro resultaba subsidiaria para las estrategias territoriales de los vizcondes, ya que sus intereses se concentraban en las tierras centrales de la Landa o la cuenca del Garona, en la zona bordelesa. Por el contrario, sus redes sociales fueron minuciosamente diseñadas teniendo en cuenta precisamente estos territorios navarros, que les permitían asociarse con familias tan importantes como los vizcondes de Béarn. La voluntad del vizconde de Tartas de estructurar un territorio y unas redes sólidas dentro del territorio gascón se vio truncada por la extinción biológica de la rama principal de la familia en 1312, pero sus estrategias habían logrado configurar un cuadro que permitiría posteriormente a sus herederos, los señores de Albret, convertirse en una de las entidades más poderosas del panorama aquitano en la Baja Edad Media.