Baghdad, also spelled Bagdad, Arabic Baghdād, formerly Madīnat al-Salām (Arabic: “City of Peace”), city, capital of Iraq and capital of Baghdad governorate, central Iraq. Its location, on the Tigris River about 330 miles (530 km) from the headwaters of the Persian Gulf, is in the heart of ancient Mesopotamia. Baghdad is Iraq’s largest city and one of the most populous urban agglomerations of the Middle East.