third century. Numidia was divided in two: Numidia Cirtensis (or Cirtense), with capital at Cirta, and Numidia Militiana ("Military Numidia"), with capital at the legionary base of Lambaesis. The newly created province was enlarged in 310 AD by the emperor Constantine. Christianity arrived early on: while little remains of African Christianity before AD200, records of Christians martyred at Cirta existed by the mid-3rd century. It became the chief town of an ecclesiastical district. Around 305, the Synod of Cirta was held to elect a new bishop, accidentally precipitating the Donatist movement. After the dissolution of its confederation of colonies in the 4th century, Cirta recovered its role as a capital when it headed the territory of Numidia Cirtensis created under Diocletian: however, after some decades, Emperor Constantine the Great reunited the two provinces created in 303 (Cirtensis & Militiana) in a single one, administered from Cirta, which was renamed Constantina (modern Constantine). Indeed, the city was destroyed after a siege by Rufius Volusianus, the praefectus praetorio of the augustus Maxentius; Maxentius's forces defeated the imperial claimant Domitius Alexander in 310. Constantine the Great rebuilt under his own name after 312 and his own victory over Maxentius in the Battle of the Milvian Bridge. Constantine made Constantina the capital of all Roman Numidia. In 320 the bishop of Cirta was accused of having handed over () Christian texts to the authorities during the Diocletianic Persecution, which had begun in 303 in Cirta. The bishop Silvanus was a Donatist and was prosecuted in December 320 by Domitius Zenophilus, the consularis and proconsul of Africa; the records of the proceedings () are preserved in the , a text collected in the Optatan Appendix. A cave for the practice of Mithraism also existed in the 4th century. In 412, Cirta was host to another important Christian council, overseen by StAugustine. According to Mommsen, Cirta was fully Latin-speaking and Christian by the time the Vandals arrived in AD430. Under the emperor , the city walls were reinforced and the city was named capital of its region with a resident commander (). Cirta was part of the Byzantine Africa from 534 to 697. Islamic conquest During the Muslim conquest of the Maghreb, Constantine was unsuccessfully defended by the Berber queen Kahina. Although many Roman, Byzantine, and Vandal cities were destroyed during the expansion of the Caliphate, Constantine survived in reduced form with a small Christian community