Of the Buildings of Justinian

"It becomes, therefore, important to have a clear record as to what Justinian did, not only in Palestine but in other countries, so as to be able to judge to some extent, by well-authenticated examples, of the founders of those edifices whose history is involved in doubt.

Of the writers who can give us this record, none has such authority as Procopius, or gives so much detailed information; and he has, for that reason, been largely quoted by Gibbon and by well-nigh every other writer on Byzantine history; and he gives such definite information as to the dates of many of Justinian's buildings which remain to us, as to form a standard by which to recognise the general characteristics in outline and detail adopted by his architects in his greatest works, and which characterize the style now well known as Byzantine." source