Among important works of the seventh century is the apse of St. Agnese, in Rome.  Honorius decorated the church, about 630, and it is one of the most effective mosaics in Rome.  At St. John Lateran, also, Pope John IV. caused a splendid work to be carried out, which has been reported as being as “brilliant as the sacred waters.”

In the eighth century a magnificent achievement was accomplished in the monastery of Centula, in Picardie, but all traces of this have been lost, for the convent was burnt in 1131.  The eighth was not an active century for the arts, for in 726 Leo’s edict was sent forth, prohibiting all forms of image worship, and at a Council at Constantinople in 754 it was decided that all iconographic representation and all use of symbols (except in the Sacrament) were blasphemous.  Idolatrous monuments were destroyed, and the iconoclasts continued their devastations until the death of Theophilus in 842.  Fortunately this wave of zeal was checked before the destruction of the mosaics in Ravenna and Rome, but very few specimens survived in France.

In the ninth century a great many important monuments were added, and a majority of the mosaics which may still be seen, date from that time:  they are not first in quality, however, although they are more numerous.  After this, there was a period of inanition, in this art as in all others, while the pseudo-prophets awaited the ending of the world.  After the year 1000 had passed, and the astonished people found that they were still alive, and that the world appeared as stable as formerly, interest began to revive, and the new birth of art produced some significant examples in the field of mosaic.  There was some activity in Germany, for a time, the versatile Bishop Bernward of Hildesheim adding this craft to his numerous accomplishments, although it is probable that his works resembled the graffiti and inlaid work rather than the mosaics composed of cubes of smalt.

At the Monastery of Monte Cassino in the eleventh century was an interesting personality,—­the Abbe Didier, its Superior.  About 1066 he brought workers from Constantinople, who decorated the apse and walls of the basilica under his direction.  At the same time, he established a school at the monastery, and the young members were instructed in the arts and crafts of mosaic and inlay, and the illumination of books.  Greek influence was thus carried into Italy through Monte Cassino.

In the twelfth century the celebrated Suger of St. Denis decorated one of the porches of his church with mosaic, in smalt, marbles, and gold; animal and human forms were introduced in the ornament.  But this may not have been work actually executed on the spot, for another narrator tells us that Suger brought home from Italy, on one of his journeys, a mosaic, which was placed over the door at St. Denis; as it is no longer in its position, it is not easy to determine which account is correct.

The mosaics at St. Mark’s in Venice were chiefly the work of two centuries and a half.  Greek artists were employed in the main, bringing their own tesserae and marbles.  In 1204 there was special activity in this line, at the time when the Venetians took Constantinople.  After this, an establishment for making the smalts and gold glass was set up at Murano, and Venice no longer imported its material.