Didymus the Blind (c. 313—c. 398) was a textual scholar and ascetic practitioner. He is not associated with any of the major ascetic settlements around Alexandria and appears to have spent his entire life in or near the city. He is most known for his treatises On the Holy Spirit and On the Trinity (although the authorship of the latter is disputed) and for his biblical commentaries.Although the Council of Nicaea in 325 took place when Didymus was still a schoolboy, controversy and competition by the parties involved continued through Didymus’ lifetime. Didymus himself supported the decision of the Council, which the Alexandrian bishop, Athanasius, had promoted. After Didymus’ death, however, he was no longer associated with the orthodoxy of the day and, because of his reception of Origen of Alexandria, was condemned, along with Origen and Evagrius Ponticus, in connection with the 2nd Council of Constantinople in 553.
Nestorius, the bishop of Constantinople, was deposed and sent into exile in Egypt for opposing the Christological views of Cyril of Alexandria. The theological and ecclesiastical controversy was set in motion soon after Nestorius began to serve as bishop of Constantinople. Interested in eliminating heresy, he proposed to align himself with the emperor Theodosius II. Soon thereafter, Nestorius learned that debates were taking place concerning the appropriate title of devotion for the Virgin Mary. In the use of the title Theotokos that some had proposed, he sensed a deeper Christological question, namely, “Was Mary the bearer of the Godhead”? He reasoned that if Mary was indeed the Theotokos, as some suggested, then God, or rather the Logos, the second person of the Trinity, was born from her. For Nestorius, however, while Mary was the mother of Jesus, she was not the mother of the Logos, and for that reason could not be called Theotokos.