 In 1085, two years after his father had conquered Graus (28 April 1083), Peter was entrusted with Sobrarbe and Ribagorza as a subkingdom with its capital at Graus, which he thenceforth ruled more or less independently with the title of king (Latin "rex").On 28 October 1087 Peter joined his father in Pamplona in Navarre, where the two monarchs confirmed the rights of the bishops in the city.He pursued the "Reconquista" with vigour in the southeast of the realm.