Scholars have long suspected that the Byzantine cult of the Virgin Mary owed its early success to the efforts of the early Byzantine empresses. Among them, it is Aelia Pulcheria, Augusta from 414 to 453 and herself a professed virgin until her politically-charged marriage in 451, who is best known for having asserted Mary’s right to be known as Theotokos - the one who gave birth to God. Many sources suggest that the Nestorian controversy debated at the Council of Ephesus in 431 arose from an altercation between Nestorius, Bishop of Constantinople from 428 to 431, and Pulcheria. On this view, the debate over Christ’s human and divine natures turned on whether Mary had given birth to God the Son, or only to Jesus the man. It was with this in mind that in 1982 Kenneth Holum suggested that by refusing to support the cult of the Virgin as Theotokos, Nestorius had in effect challenged the imperial family’s religious authority in early fifth-century Constantinople.