Behind the gorgeous marble screen which divides the presbytery from the body of the church the high altar rises beneath a canopy of _verde antico_ borne by four columns. Two of these columns are eleventh century and are elaborately carved in courses of innumerable figures. They came from Pola when Venice subdued Istria, and are much more interesting than the other two of a later date; the remains of S. Mark rest within this magnificent shrine. On the screen itself stand the Evangelist, the twelve Apostles, and Mary.
At the back of the high altar is the Pala d'Oro, the greatest treasure the cathedral possesses, and the most celebrated golden altarpiece in existence. The upper part came from Constantinople in 976, the lower about the middle of the fourteenth century. It is composed of eighty-three panels of Greek and Byzantine design filled with enamelled figures, studded with uncut gems and precious stones, and covered with Greek and Latin inscriptions. More gorgeous than that of S. Ambrogio in Milan, this magnificent piece of goldsmith's art glitters and sparkles in a wonderful manner when lit up by the candles used at high mass, and is without doubt the most splendid ecclesiastical treasure in Italy.
[Illustration: INTERIOR, S. MARK'S, VENICE]
The fifth or eastern dome which is over the presbytery is covered with mosaics representing Christ and the Prophets, and one that is hardly visible of S. Mark is on the walls of the east end. The great figure of Christ faces the church and in its simplicity is very impressive.
The gallery, which is where the triforium would be in a Gothic building, runs round the whole cathedral and is pierced on its inner side only. The walls at the back and above are decorated with more mosaic work dealing with acts of martyrdom, and the Translation and Recovery of the Body of the Lord. When stray beams of sunlight find their way through the openings in the domes and pass along the gold background, lighting up in odd places small portions of these wonderful _tesseræ_ pictures, the effect is very beautiful. All the angles of this mosaic work are rounded off and the travelling rays glinting first on one golden corner, then on another, are strangely attractive to eyes accustomed to the greater architectural severity of a northern clime. The well-chosen slabs that line the lower portions of the cathedral walls have taken to themselves a sombre, dusky hue, a pale velvety brown, but there can be no doubt that in their pristine state they realised in their splendour the Venetian's love of colour.