As the capital of the Abbasid Caliphate, Baghdad was a site of encounter that attracted people, products, and ideas from all over Afroeurasia. People from many ethnic groups and religions coexisted in the caliphate. The caliphs not only supported merchants and trade but also the collection, translation, and production of knowledge in science, mathematics, and medicine. The vibrant exchange of people, products, and ideas created new products and ideas.