work devoted to the extraction of metals and, especially the Celtic fortifications of Pendia, Los Mazos and La Escrita also prove the aforementioned pre-Roman settlements. The subsequent Roman presence, after the conquest carried out by the legions under command of General Publio Carisio (the X Gemina and the V Alaudae), left imprints such as several coins and ceramics fragments, as well as probably the origin of the names of some small villages such as Vega de Ouria, likely due to the presence of some river gold working in that time. In those days, it is believed that the area corresponding to the civil parish of Castrillón was populated by the astur tribe of Pesicos, whereas the area located western from the Navia River would have been inhabited by the gallaeci tribe of Albions. After about four centuries of Roman domination, the barbarians entered the Iberian Peninsula, and Suebi settled down in the western area of Asturias, reaching their maximum expansion about the year 450. It is known that later arrived Visigoths, that occupied the whole territory about 584. However, there are very little archaeological remains of all those populations. Middle Ages Little is known about the history of Boal at the beginning of the Middle Ages, during the asturian monarchy. The fights between the bishops of Oviedo and Lugo for the territories located between the rivers Navia and Eo came to an end by means of an agreement promoted by the king Alfonso VII. Thus, all those territories and Boal included among them were submitted to the bishop of Oviedo by donation in the year 1154, under the generic denomination of territory of Castropol. In 1368, the bishop D. Gutierre, appointed Alvar Pérez Osorio as "governor" of the Tierra de Ribadeo y Grandas, which comprised the current municipalities of Boal, Castropol, Coaña, El Franco, Grandas de Salime, Illano, Pesoz, San Martín de Oscos, Santa Eulalia de Oscos, Tapia, Taramundi and Vegadeo, having up to 41 parishes. This was a time of many violent uprisings because of the high taxes Pérez Osorio obliged the inhabitants of the area to pay. Subsequently, bishops created several villages and municipalities, so at the beginning of the 16th century, the Tierra de Ribadeo was divided into five municipalities: Castropol, Piantón, Barres, El Franco and Grandas, with Boal belonging to the municipality of El Franco. Modern Ages This system of municipalities was in force until the