Basra Eyalet in the context of "Basra"

Baghdad is the capital and largest city in Iraq. It is located on the banks of the Tigris in central Iraq. The city has an estimated population of 8 million. It ranks among the most populous and largest cities in the Middle East and the Arab world and constitutes 22% of the country's population. Baghdad is a primary financial and commercial center in the region.

Founded in 762 AD by Al-Mansur, Baghdad was the capital of the Abbasid Caliphate and became its most notable development project. The city evolved into an intellectual and cultural center. This, in addition to housing several key academic institutions, including the House of Wisdom, as well as a multi-ethnic and multi-religious environment, garnered it a worldwide reputation as the "Center of Learning". 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. It 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, shift in power and multiple successive empires. Later, Baghdad served as the administrative center of Ottoman Iraq, exercising authority over the provinces of Basra, Mosul, and Shahrizor.

Ottoman Iraq or Hıtta-i Irakiyye (Ottoman Turkish: خطهٔ عراقیه, romanized: Hıṭṭa-i ʿIrāqiyye, lit. the Iraq region) was the Ottoman name for the region of Iraq that was under their control. Historians often divide its history into five main periods. The first began with Sultan Süleyman I's conquest in 1534 and ended with the Safavid capture of Baghdad in 1623. The second lasted from the Ottoman reconquest in 1638 to the start of Mamluk self-rule in 1749. The third period, from 1749 to 1831, was marked by the Georgian Mamluk dynasty’s semi-autonomous governance. The fourth stretched from the Ottoman removal of the Mamluks in 1831 to 1869, when reformist governor Midhat Pasha took office. The fifth and final phase ran from 1869 until 1917, when British forces occupied Baghdad during the First World War.

Administratively, during the first period in the 16th century, Baghdad Eyalet encompassed much of the territory of modern Iraq. In the 17th century, the Ottomans had reorganized Iraq into four eyalets (Baghdad, Basra, Mosul, and Shahrizor). However, from the late 17th century, a trend of administrative unification began, with Basra coming under Baghdad's control from around 1705 and Mosul and Shahrizor following after 1780 during the semi-autonomous Mamluk period. Following this unification, Mamluk rulers such as Sulayman the Great were described as governing “all of Iraq”, and the Ottomans themselves began referring to the region unofficially as “the land of Iraq”. By 1830, and possibly earlier, these were being collectively referred to in official Ottoman correspondence as the region of Iraq, as attested in a letter from Sultan Mahmud II. The four eyalets were later consolidated in the 19th century into the vilayets of Mosul, Baghdad, and Basra, collectively referred to in official Ottoman documents as the Iraq Region (Hıtta-i Irakiyye).