Anbar (, ,) also known by its original ancient name, Peroz-Shapur, was an ancient and medieval town in central Iraq. It played a role in the Roman–Persian Wars of the 3rd–4th centuries, and briefly became the capital of the Abbasid Caliphate before the founding of Baghdad in 762. It remained a moderately prosperous town through the 10th century, but quickly declined thereafter. As a local administrative centre, it survived until the 14th century, but was later abandoned. Its ruins are near modern Fallujah. The city gives its name to the Al-Anbar Governorate. History Origins The city is located on the left bank of the Middle Euphrates, at the junction with the Nahr Isa canal, the first of the navigable canals that link the Euphrates to the River Tigris to the east. The origins of the city are unknown, but ancient, perhaps dating to the Babylonian era and even earlier: the local artificial mound of Tell Aswad dates to . Sasanian period The town was originally known as Misiche (Greek: ), Mesiche (), or Massice ( mšyk; mšyk). As a major crossing point of the Euphrates, and occupying the northernmost point of the complex irrigation network of the Sawad, the town was of considerable strategic significance. As the western gate to central Mesopotamia, it was fortified by the Sasanian ruler Shapur I () to shield his capital, Ctesiphon, from the Roman Empire. After his decisive defeat of the Roman emperor Gordian III at the Battle of Misiche in 244, Shapur renamed the town to Peroz-Shapur (Pērōz-Šāpūr or Pērōz-Šābuhr, from , meaning "victorious Shapur"; in ; in ). It became known as Pirisapora or Bersabora () to the Greeks and Romans. The city was fortified by a double wall, possibly through the use of Roman prisoner labour; it was sacked and burned after an agreement with its garrison in March 363 by the Roman emperor Julian during his invasion of the Sasanian Empire. It was rebuilt by Shapur II. By 420, it is attested as a bishopric, both for the Church of the East and for the Syriac Orthodox Church. The town's garrison was Persian, but it also contained sizeable Arab and Jewish populations. Anbar was adjacent or identical to the Babylonian Jewish center of Nehardea (), and lies a short distance from the present-day town of Fallujah, formerly the Babylonian Jewish center of Pumbedita (). Islamic period The city fell to