Why the Muslims didn and rsquot continue to conquer Catholic areas in the northern region of the Iberian Peninsula.?

The Muslims did not continue to conquer Catholic areas in the northern region of the Iberian Peninsula primarily due to the rise of organized Christian resistance, particularly during the Reconquista. The harsh mountainous terrain of northern Iberia made military campaigns challenging and costly. Additionally, internal divisions and shifts in power dynamics within the Muslim territories, along with the establishment of strong Christian kingdoms, contributed to the halt of further Muslim expansion into these regions.