A ruined castle, near the city, recalls its strategic importance in the 8th century, when Asturias, Galicia and Leon were the headquarters of resistance to the Moors.
Wellington had further organized the Spanish forces - Castanos (40,000), with the guerrilla bands of Mina, Longa and others, was in Galicia, the Asturias and northern Spain; Copons (io,000) in Catalonia; Elio (20,000) in Murcia; Del Parque (12,000) in the Sierra Morena, and O'Donell (15,000) in Andalusia.
Of its numerous affluents the most important is the Sil, which rises among the lofty mountains between Leon and Asturias.
The rivers of the northern versant, such as the Nera, are, like those of Asturias, for the most part short, rapid and subject to violent floods.
In 793 Hescham, the successor of Abd-al-Rahman II., proclaimed a holy war against the Christians, and collected an army of Ioo,000 men, half of which was directed against the kingdom of the Asturias, while the second invaded France, penetrating as far as Narbonne.