 Throughout this whole period, William planned to conquer Béarn, but never got around to actually launching any military expedition.In 1173, the year Sentonge was executed, Mary abandoned William with their two young twin sons and entered the monastery of Santa Cruz de Volvestre.The Bearnese, having rid themselves of three viscounts in as many years, sent a delegation to the monastery to request one of her sons to succeed to the viscounty.