Although the doctrine of Mary's Immaculate Conception appears only later among Latin (and particularly Frankish) theologians, it became ever more manifest among Byzantine theologians reliant on Gregory Nazianzen's Mariology in the Medieval or Byzantine East. Although hymnographers and scholars, like the Emperor Justinian I, were accustomed to call Mary "prepurified" in their poetic and credal statements, the first point of departure for more fully commenting on Nazianzen's meaning occurs in Sophronius of Jerusalem. In other places Sophronius explains that the Theotokos was already immaculate, when she was "purified" at the Annunciation and goes so far as to note that John the Baptist is literally "holier than all 'Men' born of woman" since Mary's surpassing holiness signifies that she was holier than even John after his sanctification in utero. Sophronius' teaching is augmented and incorporated by St. John Damascene (d. 749/750). John, besides many passages wherein he extolls the Theotokos for her purification at the Annunciation, grants her the unique honor of "purifying the waters of baptism by touching them." This honor was most famously and firstly attributed to Christ, especially in the legacy of Nazianzen. As such, Nazianzen's assertion of parallel holiness between the prepurified Mary and purified Jesus of the New Testament is made even more explicit in Damascene in his discourse on Mary's holiness to also imitate Christ's baptism at the Jordan. The Damascene's hymnongraphy and De fide Orthodoxa explicitly use Mary's "pre purification" as a key to understanding her absolute holiness and unsullied human nature. In fact, Damascene (along with Nazianzen) serves as the source for nearly all subsequent promotion of Mary's complete holiness from her Conception by the "all pure seed" of Joachim and the womb "wider than heaven" of St. Ann.
Whose teachings did Emperor Justinian I augment?