Why did the decisive successes of the Reconquista date back to the 11-13th centuries, and its completion

Why did the decisive successes of the Reconquista date back to the 11-13th centuries, and its completion became possible only at the end of the 15th century?

The reconquista began in Spain in the 11th century. Many states joined the reconquest because they wanted to reclaim their lost territories. This large-scale action was completely completed in the 15th century, because at that time there were battles with Muslim states. The Reconquista was beneficial for all Christian strata of the population, because thanks to the victories, the citizens of European states received territories. The cities gained self-government, the rulers received more wealth, the church – new parishioners, the peasants – freedom.