Nestorius was a 5th-century Christian theologian and Archbishop of Constantinople who served from 428 to 431. Born in Germanicia, he was trained in Antioch under Theodore of Mopsuestia before being appointed to his see by Emperor Theodosius II. He is primarily remembered for his controversial views on the relationship between the divine and human natures of Christ, which led to intense theological disputes with figures like Cyril of Alexandria. His teachings eventually resulted in his condemnation at the Council of Ephesus and his subsequent exile to Upper Egypt.