The young Alfonso always appears in his early charters beside his mother, Elvira García, a sister of the count of Castile and possibly exercising the regency under his influence.
In 1000, as regent, Menendo confirmed the testament of Hilal, called Salvatus, the Mozarabic abbot of San Cipriano de Valdesalce, after the queen-regent Elvira and the young king and before five bishops of the realm.