He was an energetic ruler who submitted the kingdom of Leon to his control and fought successfully against the Muslims, who still dominated most of the Iberian Peninsula.

He personally directed, before the year 910, a military expedition against the Muslims in the south of the Iberian Peninsula, which reached the city of Seville.

Although the infant Garcia, brother of Ordoño, was arrested and imprisoned in Gauzón castle, the following year Alfonso III was obliged to abdicate by his children and divide his kingdom amongst them.

Ordoño II—who had come at King Sancho's request—attributed the loss to the absence of the leading counts of Castile—Nuño Fernández, Fernando Ansúrez and Abolmóndar Albo—who had not come at his call.

He suffered frequent raids into his territory from the armies of Abd-ar-Rahman III and he confronted the Castilians who were planning a revolt in León.

His first wife, and the mother of his children, was Elvira Menéndez, daughter of count Hermenegildo Gutiérrez and aunt of San Rosendo.

He died in 924 leaving young children, and was succeeded by his eldest surviving brother, Fruela, the king of Asturias, thereby reuniting their father's patrimony.