"Before 428, theotokos is not in fact encountered in the literary œuvre of Cyril, though it is found in at least one homily of Nestorius".

Hagia Sophia

"The appellation θεοτόκος was not at all universal.  After the Council of Ephesus, it still had to be explained to the occidentals. . . . Before 428, it is not in fact encountered [(ne se rencontre pratiquement pas)] in the literary œuvre of Cyril, though it is found in at least one homily of Nestorius; . . . the Alexandrian archbishop will continue, at the height of the controversy, to call [(conservera, en pleine controverse, l’usage d’appeler)] Mary 'the Holy Virgin'."

     Joseph Famerée, "Éphèse et Nestorius:  un malentendu christologique:  l’apport du P. A. de Halleux," Revue théologique de Louvain 39, no. 1 (2008):  16-17 (3-25).