Nestorius (; in ; 386 – 450) was Archbishop of Constantinople from 10 April 428 until August 431, when the emperor Theodosius II confirmed his condemnation by the Council of Ephesus on 22 June. His teachings included a rejection of the long-used title of Theotokos, "Mother of God", for Mary, mother of Jesus, and were considered by many to imply that he did not believe that Christ was truly God. This brought him into conflict with other prominent churchmen of the time, most notably Cyril of Alexandria, whom he accused of heresy.

Nestorius (; in ; 386 – 450) was Archbishop of Constantinople from 10 April 428 until August 431, when the emperor Theodosius II confirmed his condemnation by the Council of Ephesus on 22 June. His teachings included a rejection of the long-used title of Theotokos, "Mother of God", for Mary, mother of Jesus, and were considered by many to imply that he did not believe that Christ was truly God. This brought him into conflict with other prominent churchmen of the time, most notably Cyril of Alexandria, whom he accused of heresy.