After the formulation of the Nicene Creed, its initial liturgical use was in baptism, which explains why the text uses the singular "I ..." instead of "we..." The text was gradually incorporated into the liturgies, first in the east and in Spain, and gradually into the north, from the sixth to the ninth centuries. In 1014 it was accepted by the Church of Rome as a legitimate part of the Mass. It is recited in the Western Mass directly after the homily on all Sundays and solemnities; in modern celebrations of the Tridentine Mass as an extraordinary form of the Roman Rite, the Credo is recited on all Sundays, feasts of the I class, II class feasts of the Lord and of the Blessed Virgin, on the days within the octaves of Christmas, Easter, and Pentecost, and on the "birthday" feasts of the apostles and evangelists (including the feasts of St. Peter's Chair and of St. Barnabas). It is recited in the Orthodox Liturgy following the Litany of Supplication on all occasions.