The Emirate of Granada was the last Muslim-ruled area in the Iberian peninsula. In January 1492, after a decade-long campaign, Muhammad XII of Granada (also known as "Boabdil") surrendered the Emirate to the Catholic forces led by the Catholic monarchs Ferdinand II of Aragon and Isabella I of Castile. The Treaty of Granada, signed on November 1491, guaranteed a set of rights to the Muslims of Granada, including religious tolerance and fair treatment, in return for the capitulation.