In the ninth century another great saint, Saint Theodore of Studion, was involved with a number of liturgical developments. The service books for Great Lent and Easter, the Lenten Triodion and the Flower Triodion (also called the Pentecostarion), are almost totally the work of the Studite monks, among the most famous of whom was Saint Joseph the Hymnographer. The liturgical typikon, the order of worship in the Studion Monastery, has been the normative order of worship for the entire Orthodox Church since the ninth century. As abbot of the Studion Monastery in Constantinople, the leading monastery in the Empire of his day, he had ultimate authority over about a hundred thousand monks throughout the Empire.
Also dating from the ninth century is a copy of the Divine Liturgy of Saint John Chrysostom which has the Liturgy of the Faithful in virtually the exact form in which it is celebrated in the Orthodox Church today.