The iconostasis of the cathedral was erected in 1653 on the initiative of Nikon the Patriarch. Its sixty nine icons illustrate the whole Bible history of the humankind. The upper tier –– patriarchal – depicts the period of the Old Testament, that before Christ’s incarnation. The next – prophetical tier – depicts images of prophets in front of Our Lady of Holy Sign, they hold scrolls with prophecies about Christ. In the festive row there are placed icons, dedicated to the main events of Christ’s life. The Deisis tier, reminding of the Second Coming: Christ-Pantocrator is confronted by Our Lady, John the Precursor and, according to the Greek tradition – twelve apostles.