By Rafe Calder
A mosaic is made of pieces. That sounds obvious until you ask how small, how many, what from, and set by whom. Ravenna is where those questions have been asked longest, and the sources we read give more than one answer to the last of them.
What the pieces are
Wikipedia’s article on mosaics says traditional tesserae are small, roughly square cubes of stone or hand-made glass enamel. It notes that some of the earliest mosaics used natural pebbles, and that modern work also uses shells, beads, coins and found objects.
It describes two Greco-Roman techniques. In opus vermiculatum the tesserae are 4 mm or smaller, and the work is made in a workshop as a small panel, then carried to the site and glued to a temporary support. These panels were often set into larger floors as emblemata. The article says this resembles an indirect method. In opus tessellatum the tesserae are larger and laid on site, which it calls the normal technique and which resembles a direct method.
Why Ravenna
The same article says Ravenna became the centre of late Roman mosaic art in the fifth century. The city article gives the political background: the emperor Honorius moved his court there in 402 (the page’s introduction says 401), and it served as the de facto capital for most of that century. Theodoric took the city in 493 and made it the capital of the Ostrogothic Kingdom, and he died in 526. Belisarius conquered it in 540, according to the city article, which makes it the seat of a Byzantine governor, the Exarch. The mosaic article puts the Byzantine takeover in 539. That is a year apart and we do not choose.
The mosaic article says the greatest development of Ravenna’s Christian mosaics came in the second half of the sixth century, and that the last Byzantine mosaics there are at Sant’Apollinare in Classe, dated 673 to 679.
The listing
UNESCO inscribed the Early Christian Monuments of Ravenna in 1996. The listing is a serial property of eight monuments, built in the fifth and sixth centuries, and the page says they show “great artistic skill” blending Greco-Roman, Christian, and Eastern and Western styles. The eight are the Mausoleum of Galla Placidia, the Neonian Baptistery, Sant’Apollinare Nuovo, the Arian Baptistery, the Archiepiscopal Chapel, the Mausoleum of Theodoric, San Vitale and Sant’Apollinare in Classe. We treat them here as buildings and craft, and say nothing about their doctrine.
One small building, several dates
Wikipedia’s article on the Mausoleum of Galla Placidia gives its date as 425 to 450 in the introduction and “after 425” in the body. The mosaic article dates the mausoleum’s mosaics, on a blue background, to 425 to 430. The Italian tourism site Italia.it says it was built in 402 under Honorius for his sister. Three sources, three framings, and none of them from the building’s own records.
The article says the plan is cruciform, with a central dome on pendentives and barrel vaults over the four arms, and a brick exterior with blind arcades. Glass tesserae cover the vaults, lunettes and cupola. In the dome it describes a starry sky of golden stars on dark blue with a gold cross at the apex. The page does not say how many stars there are. The alabaster window panels, it says, are modern, and the floor has been raised about five feet since the fifth century because of rising water along the upper Adriatic.
The name is another puzzle. The article says that Galla Placidia died and was probably buried in Rome, and calls the Ravenna burial claim a misconception that goes back to the Liber Pontificalis. It also says the three sarcophagi are only “attributed” to named people. The building is called her mausoleum all the same. Our reading: a name that sticks can outlast the evidence for it.
Dates in order
- 402: Honorius moves his court to Ravenna (401 in the page’s introduction), according to Wikipedia.
- 425 to 430: mosaics of the Galla Placidia mausoleum, according to Wikipedia’s mosaic article.
- 493: Theodoric takes Ravenna, according to Wikipedia.
- 526: Theodoric dies, according to Wikipedia.
- 539 or 540: Byzantine conquest, according to the mosaic article and the city article respectively.
- 673 to 679: the last Byzantine mosaics at Sant’Apollinare in Classe, according to Wikipedia.
- 1996: UNESCO inscription.
Side by side
- Stone against glass: Wikipedia names both as traditional tesserae. The Galla Placidia article specifies glass for that building.
- Workshop against site: vermiculatum is made off site and carried; tessellatum is laid in place.
- Our reading: when someone sells you a mosaic, the first question is which of these two ways it was made. No source we read says how to tell by looking.
What kind of sources these are
UNESCO’s World Heritage page; three Wikipedia articles, which anyone can edit; and the national tourism site. Wikipedia carries the technique and the building detail. The mosaic article itself has errors in its dating of other sites, so we used only its Ravenna and technique passages.
What we left out
We left out admission arrangements, guided tours and prices. We left out the mosaics’ religious subjects, the sarcophagus fire of 1577, the burial story’s details and any schools or workshops, because our sources did not cover them.
Quick answers
What are Ravenna’s mosaics made of? Small cubes of stone or hand-made glass, called tesserae. The Galla Placidia mausoleum uses glass tesserae, according to Wikipedia.
When did UNESCO list Ravenna’s monuments? In 1996, as a serial property of eight early Christian monuments, according to UNESCO’s World Heritage page.
When was the Galla Placidia mausoleum built? Wikipedia says 425 to 450 or after 425. The tourism site Italia.it says 402. The sources disagree.
Related on this site: bologna-porticoes-unesco-covered-walks, aceto-balsamico-tradizionale-modena-dop-label, castelfidardo-accordion-soprani-reeds
Roam first. Shop later.