Бану Каси
In 918, Sancho combined with Ordoño II of León to attack the Upper March. Though they failed to occupy Nájera, they took Calahorra, Arnedo and Viguera from the Banu Qasi, and attacked Valtierra, and though they failed to take its fortress, they burned it's mosque and surrounding lands. Two years later Sancho teamed with Bernard I of Ribagorza and Amrus ibn Muhammed, son of Muhammad al-Tawil, to attack Banu Qasi-held Monzón. His successes allowed him to join Lower Navarre to his own dominions and extend his territory as far as Nájera. As a thanksgiving offering for his victories, in 924 he founded the monastery of San Martín de Albelda.