[3] Mary and a delegation of Bearnese nobles accepted an oath containing several newly inserted clauses of Alfonso's making which asserted the Crown of Aragon's absolute rights and total control over and above the three viscounties of Béarn, Gabardan, and Brulhois.

In March 1171, the Catalan William of Montcada did homage to Alfonso for Béarn, implicitly as Mary's husband.

Immediately they elected Theobald of the neighboring County of Bigorre as their viscount, but, as he did not respect the Fors de Bearn, they executed him within the year.

They then selected a nobleman of the Auvergne, Sentonge, who lasted two years in power before suffering the same sad fate at the hands of the nobles.

In 1173, the year Sentonge was executed, Mary abandoned her husband, taking their young twin sons with her, and entered the monastery of Santa Cruz de Volvestre.