Qinnasrin (Arabic: ; Syriac: , romanized: Qinna?r?n, lit. 'Nest of Eagles'), also known by numerous other romanizations[n 1] and originally known as (Latin: Chalcis ad Belum;Greek: , Khalkìs), was a historical town in northern Syria. The town was situated 25 km south west of Aleppo on the west bank of the Queiq River (historically, the Belus) and was connected to Aleppo with a major road during Roman times.
According to Appian, Chalcis was founded by Seleucus I Nicator, and named after Chalcis in Euboea. Chalcis was distinguished from Chalcis sub Libanum by its river, the ancient Belus. The river--but not the city[n 2]--was named for the Semitic god Bel or Ba?al. In 92 AD, Chalcis received the title "Flavia", in honor of Emperor Domitian, to be known as "Flavia of the Chalcidonese".
The city was a Christian bishopric from an early stage, at first a suffragan of Seleucia Pieria, but later raised to the dignity of autocephalous archdiocese. The names of several of its bishops are known, from that of 3rd-century Tranquillus to that of Probus, who lived at the end of the 6th century and whom Emperor Mauritius Tiberius sent as his envoy to the Persian king Chosroes I.
In Late Antiquity, it belonged to the province of Syria Prima. Its importance was due to its strategic location, both as a caravan stop and as part of the frontier zone (limes) with the desert. In 540, the Sassanid shah Khosrau I appeared before the city and extracted 200 pounds of gold as ransom in return for sparing the city. This prompted the Emperor Justinian I to order its fortifications rebuilt, a work undertaken by Isidore the Younger (a nephew of Isidore of Miletus) in ca. 550.
Under the Umayyad Caliphate, the city became the center of one of the districts into which Arab Syria was divided, the Jund Qinnasrin. The town was repeatedly attacked and sacked by the Byzantines during the latter stages of the Arab-Byzantine wars, in 966, 998 and 1030, and then destroyed by the Seljuq Turks towards the end of the 11th century. Qinnasrin never recovered from the latter, and survived only as an arsenal and caravansarai before being finally deserted.