S.Theodore's church, which stood originally on a part of the Piazza (an inscription in the pavement marks the site) now covered by the Campanile and one or two of the flagstaffs, is supposed to have been built in the sixth century.

That it was destroyed by fire in the tenth, we know, and it is known too that certain remains of it were incorporated in the present structure of S.
Mark's, which dates from the eleventh century, having been preceded by earlier ones.
To my mind not one of the external mosaic pictures is worth study; but some of the mosaic patterns over the doors are among the most lovely things I ever saw.

Look at the delicate black and gold in the arch over the extreme right-hand door.

Look at the black and gold bosses in that next it.

On the other side of the main entrance these bosses have a little colour in them.