In 980, during the reign of Emperor
Basil II, when Nicholas II was Ecumenical Patriarch, the
Archangel Gabriel was believed to have appeared in the guise of a monk to the disciple of a certain monk at the
Monastery of the Pantocrator in
Mount Athos. The monk reported that the angel sang a new verse of the matins hymn, recorded on a slate still held at the monastery. Nicholas II received the relic in the cathedral of
Hagia Sophia. The
Axion Estin is still sung in Orthodox services. Nicholas II's tenure also saw the completion of the
Christianisation of Kievan Rus' and the appointment of the first metropolitan for Rus',
Michael I of Kiev. Patriarch Nicholas II was later canonised and is commemorated by both the
Catholic Church and the
Eastern Orthodox Church on 16 December. == Notes and references ==