This is historically inaccurate. The title of Theotokos, meaning birth-giver to God, was in use long before Nestorius came to power, used violence to force people to refer to the Blessed Virgin Mary as “Christokos” and then to justify this change, he argued a separation between the deity and humanity of our Lord, and was subsequently deposed and anathematized for this at the Council of Ephesus, based on the consensus of the three other major patriarchates (including Antioch, where he had originally been ordained).
You should perhaps read up on ecclesiastical history. I would suggest the Cambridge History of the Christian Church (I have all eight volumes), the Oxford History of Christian Worship, and when it comes to Eastern Orthodoxy, The Orthodox Church by Metropolitan Kallistos Ware, memory eternal, who contributed to the Orthodox Study Bible which I can’t recall if you have in addition to the NETS translation of the Septuagint.
I will let
@Ain't Zwinglian and
@MarkRohfrietsch recommend a good history of the Reformation and Martin Luther. As for a history of the Oriental Orthodox, my friend dzheremi can suggest one perhaps, but I am not going to tag him - the Coptic Orthodox Church (which included until recently the Ethiopian and Eritrean churches, but granted these what we call
autocephaly, meaning ecclesiastical independence, in the 20th century) and the Syriac Orthodox Church and the Armenian Apostolic Church collectively have done much to preserve the ancient Christology that was upheld at the Council of Ephesus.
The problematic overreaction to Nestorius was Eutyches, who together with the sinister crypto-Nestorian Ibas, who played both sides of the fence, deceived various bishops which contributed to the disastrous EO-OO schism as a result of the Oriental Orthodox being falsely accused of Eutychianism (Eutyches taught that the human nature of our Lord was dissolved into His divinity “like a drop of water in the ocean” and this violates the fourfold principle of Jesus Christ being fully man and fully God without change, confusion, separation or division. Eutychianism, also known as Monophysitism, which degenerated into Tritheism, embraces the first two categories, and Nestorianism the subsequent categories.