the Demonstrations of the slightly older Aphrahat and the anonymous ascetical Book of Steps. Ephrem lived in the Roman Empire, close to the border with the Sasanian Empire, to which the other two writers belonged. However, another source claims there is a significant amount of evidence from the fourth century and before about liturgical practices. Other items of early literature of Syriac Christianity are the Diatessaron of Tatian, the Curetonian Gospels and the Syriac Sinaiticus, the Peshitta Bible and the Doctrine of Addai. The bishops who took part in the First Council of Nicea (325), the first of the ecumenical councils, included twenty from Syria and one from Persia, outside the Roman Empire. Two councils held in the following century divided Syriac Christianity into two opposing parties. East-West theological contrast Syriac Christianity is divided on several theological issues, both Christological and Pneumatological. In 431, the Council of Ephesus, which is reckoned as the third ecumenical council, condemned Nestorius and Nestorianism. That condemnation was consequently ignored by the East Syriac Church of the East, which had been previously established in the Sasanian Empire as a distinct Church at the Council of Seleucia-Ctesiphon in 410, and which at the Synod of Dadisho in 424 had declared the independence of its head, the Catholicos, in relation to "western" (Roman Empire) Church authorities. Even in its modern form of Assyrian Church of the East and Ancient Church of the East, it honours Nestorius as a teacher and saint. In 451, the Council of Chalcedon, the fourth ecumenical council, condemned Monophysitism, and also rejected Dyoprosopism. This council was rejected by the Oriental Orthodox Churches (among which is the Syriac Orthodox Church) that use the West Syriac Rite. The Patriarchate of Antioch was consequently divided between two communities, pro-Chalcedonian and non-Chalcedonian. The Chalcedonians were often labelled as 'Melkites' (Imperials), while their opponents were labelled Monophysites (those who believe in the one rather than two natures of Christ) and Jacobites (after Jacob Baradaeus). In 553, the Council of Constantinople, the fifth ecumenical council, anathematized Theodore of Mopsuestia, and also condemned several writings of Theodoret of Cyrus and Ibas of Edessa (see: Three-Chapter Controversy). Since those three theologians were highly regarded among Eastern Syriac Christians, further rifts were created, culminating in 612, when a major council of the Church of the East was held in Seleucia-Ctesiphon. Presided by Babai the Great (d. 628), the council officially adopted specific