51.] The foundation of a new capital is naturally connected with the establishment of a new form of civil and military administration.
The distinct view of the complicated system of policy, introduced by Diocletian, improved by Constantine, and completed by his immediate successors, may not only amuse the fancy by the singular picture of a great empire, but will tend to illustrate the secret and internal causes of its rapid decay.

In the pursuit of any remarkable institution, we may be frequently led into the more early or the more recent times of the Roman history; but the proper limits of this inquiry will be included within a period of about one hundred and thirty years, from the accession of Constantine to the publication of the Theodosian code; [71] from which, as well as from the Notitia [71a] of the East and West, [72] we derive the most copious and authentic information of the state of the empire.

This variety of objects will suspend, for some time, the course of the narrative; but the interruption will be censured only by those readers who are insensible to the importance of laws and manners, while they peruse, with eager curiosity, the transient intrigues of a court, or the accidental event of a battle.
[Footnote 71: The Theodosian code was promulgated A.D.438.

See the Prolegomena of Godefroy, c.i.p.

185.] [Footnote 71a: The Notitia Dignitatum Imperii is a description of all the offices in the court and the state, of the legions, &c.