The great many mosaic scenes in the atrium and interior are accompanied by inscriptions that enrich and broaden the spiritual meaning of the mosaics themselves.
All the scenes feature a literary text in Latin, mostly drawn from the books of the Old and New Testaments. There are mediaeval prayers or invocations. The individual figures of the saints are also accompanied by their names.
Over and above the Latin inscriptions there are a few in Greek. These are associated with the numerous images of Jesus and the Virgin, always accompanied by their monograms.

FURTHER INFORMATION

The inscriptions accompanying the mosaics and the numerous Old and New Testament figures are a little known aspect of the church’s decoration but they are extremely important because they comment on and complete each of the very many scenes, broadening their spiritual meaning.
Almost all of the mosaic inscriptions are in Latin.
There are a very few in Greek, among which the monograms of Christ and the Virgin which accompany all images of them almost as if to underline their superiority; the names next to some images of St. Peter, St. Paul, St. John the Evangelist, the archangels Michael and Gabriel and some of the Fathers of the Eastern Church, and the title of the Anastasis, the descent to the infernal regions, on the west vault of the Ascension cupola. There are few others.

All the Latin inscriptions come under one of the following classifications:
1) biblical passages, quoted textually or summarised in prose or verse, illustrating individual scenes or written on the prophets’ scrolls;
2) mediaeval texts in verses that express prayers or invocations; appearing on arches, semi-domes and vaulted ceilings, they are very often addressed to St. Mark and composed specially for the church;
3) prose texts illustrating individual scenes;
4) names of prophets and saints next to each individual image.

By way of example let us analyse the central portal area that leads into the church from the atrium.
Around this portal there are four niches containing figures of the four evangelists in canonical order: Matthew, Mark, Luke and John, considered to be among the oldest mosaic creations of the late 11th century.
On the upper part of the niches four hemistichs recite: Ecclesiae Christi vigiles / sunt quattuor isti / quorum dulce melos / sonat et movet udique coelos (these four are “sentinels” of the church of Christ, their sweet song resounds and everywhere moves the heavens).
Above, set in a smaller register, the images of eight apostles, these too of very ancient date, surrounding the Virgin to whom the horizontal inscription refers, rendering her a symbolic figure of the Church: Sponsa Deo gigno natos ex virgine virgo / quos fragiles firmo fortes super aethera mitto (Bride of God, virgin always, I generate children whom I fortify in their weakness and send safely to heaven).
On the front of the great semi-dome over the portal , the prayer is addressed directly to Mark, Holy Evangelist and patron saint of the city, depicted in a 16th century mosaic. In liturgical vestments he welcomes the faithful to his church: Alapis Marce delicta precantibus arce / ut surgant per te factore suo miserante (O Mark, banish sins from those who pray to you with clasped hands; through your intervention and God’s mercy they may achieve salvation).
Above the same portal, on the inside, a 13th century mosaic lunette shows the Virgin Mary and St. Mark in the act of interceding on man’s behalf with Jesus who is portrayed as Christ Pantocrator, lord and judge of the universe. The words of the Gospel of St. John are clearly visible in the book and give us the right interpretative key to the figure of Jesus who says of himself: Ego sum ostium, si quis per me introierit salvabitur et pasqua inveniet (I am the gate; whomsoever enters through me shall find the pastures of salvation). So the opening through which one passes from outside to inside the church is a clear symbol of the true “gate” to the Kingdom of God, the person of Jesus himself.
Observing, lastly, the numerous figures of prophets, apostles and saints one notes that each one’s name is inscribed, in accordance with a practice typical of oriental icons painted on wood in which the name had to appear together with the figure. Once again the inscriptions are in Latin, demonstrating that Venice, though open to Byzantine influence, was firmly rooted in a western cultural environment.