at the capital. He erected great public buildings, which were not
only useful but ornamental to the city. The most remarkable of
them was the very magnificent cathedral of St. Sophia (So-phi'-a),
for a long time the grandest church structure in the world. The
great temple still exists in all its beauty and grandeur, but is
now used as a Mohammedan mosque.

But the most important thing that Justinian did--the work for
which he is most celebrated--was the improving and collecting of
the laws. He made many excellent new laws and reformed many of
the old laws, so that he became famous as one of the greatest of
the world's legislators. For a long time the Roman laws had been
difficult to understand. There was a vast number of them, and
different writers differed widely as to what the laws really were
and what they meant. Justinian employed a great lawyer, named
Tribonian (trib-o'-ni-an), to collect and simplify the principal
laws. The collection which he made was called the CODE OF JUSTINIAN.
It still exists, and is the model according to which most of the
countries of Europe have made their laws.

Justinian also did a great deal of good by establishing a number
of manufactures in Constantinople. It was he who first brought
silk-worms into Europe.

To the last year of his life Justinian was strong and active and
a hard worker. He often worked or studied all day and all night
without eating or sleeping. He died in 565 at the age of eighty-three
years.