Baghdad is the capital of Iraq and the second-largest city in the Arab world after Cairo. Located along the Tigris River, the city was founded in the 8th century and became the capital of the Abbasid Caliphate. Within a short time of its inception, 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".
Baghdad was the largest city in the world for much of the Abbasid era during the Islamic Golden Age, peaking at a population of more than a million. The city was largely destroyed at the hands of the Mongol Empire in 1258, resulting in a decline that would linger through many centuries due to frequent plagues and multiple successive empires. With the recognition of Iraq as an independent state in 1932, Baghdad gradually regained some of its former prominence as a significant center of Arabic culture, with a population variously estimated at 6 or over 7 million.