Baghdad is capital and largest city of Iraq. Located on the Tigris, the city is part of the Baghdad Governorate. It has a population variously estim…Baghdad is capital and largest city of Iraq. Located on the Tigris, the city is part of the Baghdad Governorate. It has a population variously estimated at 6 or over 7 million. Compared to its large population, the city has a small area at just 673 square kilometers. Baghdad is popular for being a center in the Islamic world. Baghdad the second-largest city in the Arab world after Cairo and the second-largest city in West Asia after Tehran.