The will of Alfonso II, known as the Testamentum regis Adefonsi, records the donations made by the king to the Cathedral of Oviedo on November 16, 812. This document, preserved in the Cathedral Archive of Oviedo, consists of nine folios arranged in two columns, written in Carolingian script.

At the beginning of the text, a stylized polychrome green cross is depicted, adorned with small pearls at the ends of its arms and featuring the Alpha and Omega. The testament opens with a detailed paragraph regarding the offerings and prayers to God. The donation encompasses various religious objects, including silver crosses, veils, altar frontals, tunics, silver reliquaries, and lamps, along with the entire church atrium, its houses, the aqueduct, and several associated buildings. An important biblical quote is included, stating: “Everything is yours, Lord, and we only give you what we have received from you.”

The testament is particularly significant as it reflects on the disappearance of the Visigoth kingdom, alluding to the sins of the Visigoth people and highlighting the need to rebuild a strong state that would ensure the recovery of the Church.