No other church has had much more than a tithe of such toil.

The Sistine Chapel in Rome is wonderful enough, with its frescoes; but what is the labour on a fresco compared with that on a mosaic?
Before every mosaic there must be the artist and the glass-maker; and then think of the labour of translating the artist's picture into this exacting and difficult medium and absolutely covering every inch of the building with it! And that is merely decoration; not structure at all.
There are mosaics here which date from the tenth century; and there are mosaics which are being renewed at this moment, for the prosperity of the church is continually in the thoughts of the city fathers.

The earliest is that of Christ, the Virgin, and S.Mark, on the inside wall over the central door.

My own favourites are all among the earlier ones.
Indeed, some of the later ones are almost repulsively flamboyant and self-conscious.

Particularly I like the great scene of Christ's agony high up on the right wall, with its lovely green and gold border, touched with red.