Business partnerships would be made for many commercial ventures, and bonds of kinship enabled trade networks to form over huge distances. Muslims were involved in trade extending into Asia, and Muslim merchants traveled long distances for commercial activities. After 800 years of warfare, the Catholic kingdoms gradually became more powerful and eventually expelled the Moors from the peninsula. In the case of the Kingdom of Portugal it happened in the 13th century; in the Algarve. The combined forces of Portugal, Aragon and Castile defeated the last Iberian Muslim strongholds in the 15th century.