upon a wooden panel, which he had himself to make, plane flat, and
cut to the size he needed. In order to get a surface upon which he
could paint, he covered the panel with a thin coating of plaster which
it was difficult to lay on absolutely flat. Upon the plaster he drew
the outline of the figures he was going to paint, and filled in the
background with a thin layer of gold leaf, such as is to-day used for
gilding frames. After the background had been put in, it was impossible
to correct the outline of the figures, and the labour of preparing
the wooden panel and of laying the gold was so great that an artist
would naturally not make risky attempts towards something new, lest
he should spoil his work. In the Jerusalem Chamber of Westminster Abbey
there is a thirteenth-century altar-piece of this kind, and you can
see the strips of vellum that were used to cover the joins of the
different pieces of wood forming the panel, beneath the layer of
plaster, which has now to a great extent peeled off.

The people liked to see their Old Testament stories and the stories
from the Life of Christ painted over and over again. They had become
fond of the versions of the tales which they had known and seen painted
when they were young, and did not wish them changed, so that the range
of subjects was not large. The same were repeated, and because of the
painter's fear of making mistakes it was natural that the same figures
should be repeated too. Thus, whatever the subject pictured, a
tradition was formed in each locality for the grouping and general
arrangement of the figures, and the most authoritative tradition for
such typical groupings was preserved in Constantinople or Byzantium,
from which city the 'Byzantine' school of painting takes its name.

Before 1200, Byzantium had been a centre of residence and the
civilizing influence of trade for eighteen centuries. It had been the