He married Sancha, an illegitimate daughter of Fernando Pérez de Traba and Theresa, Countess of Portugal.
She died around 1182, having left Álvaro two sons, Rodrigo and Vermudo, and two daughters, Sancha and Teresa, who married Alfonso Ramírez.
Álvaro is first mentioned in a document of 29 January 1129 in the Tumbo de Lorenzana, the cartulary of the monastery of Lourenzá.
[2] On 13 February 1161 Álvaro was carrying the title "count" (Latin comes), the highest in the kingdom, for the first time.
He patronised the Cistercian monastery of Meira, where nearby he had received a grant of property from Alfonso VII on 27 August 1151.