Narthex
Originally, the narthex embraced the western arm of the basilica on the three sides; later the southern part was closed to obtain the Baptistery (14th century) and the Zen Chapel (16th century). The narthex prepare the visitors’ eyes to the suffused atmosphere of the gilded interior, just like the Old Testament stories represented in its mosaic ceiling prepare to the Gospel of the basilica’s. The main subjects are Genesis and the life of Noah, Abraham, Joseph, Moses. Beside the main portal remain the Evangelists, 11th century mosaics that decorated the entrance to St Mark’s even before the narthex was built.
Read more about this topic: St Mark's Basilica