For centuries, the capital, Baghdad was the Medieval centre of the literary and artistic Arab world, but its artistic traditions suffered at the hands of the Mongol invaders in the 13th century. Baghdad evolved into a significant cultural, commercial, and intellectual center of the Muslim world. This, in addition to housing several key academic institutions, including the House of Wisdom, as well as hosting a multiethnic and multireligious environment, garnered the city a worldwide reputation as the "Centre of Learning".