Raqqa (, also and ) is a city in Syria on the left bank of the Euphrates River, about east of Aleppo. It is located east of the Tabqa Dam, Syria's largest dam. The Hellenistic, Roman, and Byzantine city and bishopric Callinicum (formerly a Latin and now a Maronite Catholic titular see) was the capital of the Abbasid Caliphate between 796 and 809, under the reign of Harun al-Rashid. It was also the capital of the Islamic State from 2014 to 2017. With a population of 531,952 based on the 2021 official census, Raqqa is the sixth largest city in Syria. During the Syrian Civil War, the city was captured in 2013 by the Syrian opposition and then by the Islamic State. ISIS made the city its capital in 2014. As a result, the city was hit by airstrikes from the Syrian government, Russia, the United States, and several other countries. Most non-Sunni religious structures in the city were destroyed by ISIS, most notably the Shia Uwais al-Qarni Mosque, while others were converted into Sunni mosques. On , following a lengthy battle that saw massive destruction to the city, the Syrian Democratic Forces (SDF, a coalition fighting the government) declared the liberation of Raqqa from the Islamic State to be complete. History Hellenistic and Byzantine Kallinikos The area of Raqqa has been inhabited since remote antiquity, as attested by the mounds (tells) of Tall Zaydan and Tall al-Bi'a, the latter being identified with the Babylonian city Tuttul. The modern city traces its history to the Hellenistic period, with the foundation of the city of Nikephorion (, Latinized as Nicephorion or Nicephorium) by Seleucid King Seleucus I Nicator (reigned 301–281 BC). His successor, Seleucus II Callinicus (r. 246–225 BC), enlarged the city and renamed it after himself as Kallinikos (, Latinized as Callinicum). Isidore of Charax, in the Parthian Stations, writes that it was a Greek city, founded by Alexander the Great. In Roman times, it was part of the Roman province of Osrhoene but had declined by the fourth century. Rebuilt by Byzantine Emperor Leo I (r. 457–474 AD) in 466, it was named Leontopolis (in Greek Λεοντόπολις or "city of Leon") after him, but the name Kallinikos prevailed. The city played an important role in the Byzantine Empire's relations with Sassanid Persia and the wars fought between the two empires. By treaty, the city was recognized as one of