It is traditionally regarded as the foundational event of the Kingdom of Asturias and thus the initial point of the Christian Reconquista ("reconquest") of Spain after the Umayyad conquest of 711.

[6] According to texts written by Mozarabs in northern Hispania during the late ninth century, the Visigoths in 718 elected a nobleman named Pelagius (c.685–737) as their princeps, or leader.

Pelagius, the first monarch of the Asturian Kingdom, son of Favila, who had been a dignitary at the court of the Visigoth King Egica (687–700), established his headquarters at Cangas de Onís, Asturias and incited an uprising against the Umayyad Muslims.

[7] Pelagius's first acts were to refuse to pay the jizya (tax on non-Muslims) to the Muslims any longer and to assault the small Umayyad garrisons that had been stationed in the area.

Reluctant to return to Córdoba with such unalloyed bad news, the Umayyad wāli, Anbasa ibn Suhaym al-Kalbi, decided that putting down the rebellion in Asturias on his way home would afford his troops an easy victory and raise their flagging morale.

As Alqama overran much of the region, folklore[9] suggests that Oppas attempted to broker the surrender of his fellow Christians, but he failed in the effort.

The Asturians shot arrows and stones from the slopes of the mountains, and then, at the climactic moment, Pelagius personally led some of his soldiers out into the valley.

[citation needed] In the aftermath of Pelagius's victory, the people of the conquered villages of Asturias now emerged with their weapons, and killed hundreds of Alqama's retreating troops.