The mountainous area of Asturias, isolated from the rest of the Iberian Peninsula, would have remained a backwater were it not for a singular event that transformed it into the most significant area of Spain: After the Moorish invasion of A.D. 711, Asturias offered a resistance only rivaled by that which they previously offered the Romans. The Moors overran the region as they had done in the rest of Iberia, except for the single, small stronghold of La Peña in the Cantabrian Mountains, perhaps the last portion of the peninsula which remained in Christian hands.