For much of the Abbasid era, during the Islamic Golden Age, Baghdad was one of the largest cities in the world and rivaled Chang'an, as the population peaked at more than one million.

Archaeological evidence shows that the site of Baghdad was occupied by various peoples long before the Arab conquest of Mesopotamia in 637 CE, and several ancient empires had capitals located in the surrounding area.

The Muslim historian al-Tabari reported an ancient prediction by Christian monks that a lord named Miklas would one day build a spectacular city around the area of Baghdad.

[23] The city's growth was helped by its excellent location, based on at least two factors: it had control over strategic and trading routes along the Tigris, and it had an abundance of water in a dry climate.

[31] There was a large sanitation department, many fountains and public baths, and unlike contemporary European cities at the time, streets were frequently washed free of debris and trash.

[citation needed] Notable scholars based in Baghdad during this time include translator Hunayn ibn Ishaq, mathematician al-Khwarizmi, and philosopher Al-Kindi.

[48][49][50] Baghdad was also a significant center of Islamic religious learning, with Al-Jahiz contributing to the formation of Mu'tazili theology, as well as Al-Tabari culminating in the scholarship on the Quranic exegesis.

[56] Baghdad's early meteoric growth eventually slowed due to troubles within the Caliphate, including relocations of the capital to Samarra (during 808–819 and 836–892), the loss of the western and easternmost provinces, and periods of political domination by the Iranian Buwayhids (945–1055) and Seljuk Turks (1055–1135).

It has recently come to light that the famed Fatimid da'i, al-Mu'ayyad al-Shirazi, had a direct role in supporting al-Basasiri and helped the general to succeed in taking Mawṣil, Wāsit and Kufa.

Under the Ottomans, Baghdad continued into a period of decline, partially as a result of the enmity between its rulers and Iranian Safavids, which did not accept the Sunni control of the city.

[73] In 1920, Baghdad became the capital of the Mandatory Iraq under the Mandate of Mesopotamia, with several architectural and planning projects commissioned to reinforce this administration.

[83] King Faisal II, former Prime Minister Nuri al-Said, former Regent Prince Abd al-Ilah, members of the royal family, and others were brutally killed during the coup.

[88] Iran launched a number of missile attacks against Baghdad in retaliation for the Iraqi Army's continuous bombardments of Tehran's residential districts.

Religious and ethnic minorities, such as Christians, Mandaeans, and Jews, began leaving the city out of fear of being targeted in the attacks, as they were subjected to kidnappings, death threats, and violence.

[97] Coinciding the execution of Saddam Hussein in 2006, violence increased in Baghdad during the sectarian civil war between Shi'ite militias and Sunni insurgents.

[98] Shi'ite militias were Muqtada as-Sadr’s Jaysh al-Mahdi (JAM) or Iranian-backed Special Groups and among Sunni insurgents, the largest was Al-Qaeda in Iraq (AQI).

[102] The city attracted global media attention on 3 January 2020, when Iranian general Qasem Soleimani was assassinated in a U.S. drone strike near Baghdad Airport.

The land on which the city is built is almost entirely flat and low-lying, being of quaternary alluvial origin due to periodic large flooding of the Tigris river.

[124] The 2013–2017 war following the Islamic State's invasion in 2014 caused hundreds of thousands of Iraqi internally displaced people to flee to the city.

[145] Majority of the country’s 15,000 Jews lived in Baghdad during Saddam Hussein’s rule and their population dwindled, not due to persecution but because of lifted travel restrictions that allowed many to emigrate.

[164] Some of the private projects includes Baghdad Renaissance Plan, Sindbad Hotel Complex and Conference Center, and Central Bank of Iraq Tower.

The proposed Baghdad Metro system includes seven main lines with a total length of more than 148 kilometres, 64 metro stations, four workshops and depots for trains, several operations control centers (OCC) and seven main power stations (MPS) with a capacity of 250 mega-watts, and several Global System for Mobile Communication (GSM) towers.

[181] In July 2024, it was announced that an international consortium of German French, Spanish, and Turkish companies was awarded $17.5 billion contract to construct Baghdad's metro.

Urban features such as streets, avenues, alleyways and squares clusters a large number of landmarks, which itself creates an identity of cultural or intellectual hubs and define the beauty of Baghdad.

[189] The place and its surroundings is where the historical features and cultural capitals of Baghdad are concentrated, from the Mutanabbi Street, Abbasid-era palace and bridges, Ottoman-era mosques to the Mustansariyah Madrasa.

[189] It is characterized by the iconic clock tower which was donated by George V.[189] The entire area is submitted to the UNESCO World Heritage Site Tentative list.

[194][195] It contains the tombs of the seventh and ninth Twelver Shi'ite Imams, Musa al-Kadhim and Muhammad at-Taqi respectively, upon whom the title of Kādhimayn ("Two who swallow their anger") was bestowed.

[204][205] Eventually Paul Bremer, Director of the Coalition Provisional Authority in Iraq after the invasion, ordered protection for the zoo and enlisted U.S. engineers to help reopen the facility.

Famous Arab poets and singers such as Nizar Qabbani, Umm Kulthum, Fairuz, Salah Al-Hamdani, Ilham al-Madfai and others have performed for the city.

[215] Baghdad is home to some of the most successful football (soccer) teams in Iraq, the biggest being Al-Shorta (Police), Al-Quwa Al-Jawiya (Air Force), Al-Zawraa, and Al-Talaba (Students).