The Praetorian Praefect, whose office had been at first a purely military one, had now for centuries been chiefly concerned in civil administration, and as Judge over the highest court of appeal in the Empire. His _Officium_ (or staff of subordinates) was, at any rate in the Fifth Century, still the most complete and highly developed that served under any great functionary; and probably the career which it offered to its members was more brilliant than any that they could look for elsewhere. Accordingly, in studying the composition of this body we shall familiarise ourselves with the type to which all the other _officia_ throughout the Empire more or less closely approximated. NOTITIA. CASSIODORUS LYDUS (xi.). (iii. 3 and ii. 18.). Princeps. Cornicularius. Cornicularius. Cornicularius. Adjutor. Primiscrinius. II Primiscrinii. Commentariensis. Scriniarius Actorum. Ab Actis. Cura Epistolarum. IV Numerarii. Scriniarius Curae Militaris. Subadjuva. Primicerius Exceptorum. Cura Epistolarum. Sextus Scholarius. Regerendarius. Praerogativarius. Exceptores. Commentariensis. II Commentarisii. Adjutores. Regendarius. II Regendarii. Singularii. Primicerius Deputatorum. II Curae Epistolarum Ponticae. Primicerius Augustalium. Primicerius Singulariorum. Singularii. Lydus calls all the officers down to the Curae Ep. Ponticae [Greek: Hai Logikai Leitourgiai] (Officium Litteratum). [Sidenote: Sources of information as to the Officium.] Our chief information as to this elaborate official hierarchy is derived from three sources[121]:-- [Footnote 121: See Table, p. 94.] (1) The _Notitia Dignitatum_, the great Official Gazetteer of the Empire[122], which in its existing shape appears to date from the reign of Arcadius and Honorius, early in the Fifth Century. [Footnote 122: To use a modern illustration, we might perhaps say that the Notitia Dignitatum = Whitaker's Almanac + the Army List.] (2) The _De Magistratibus_ of Joannes Lydus, composed by a civil servant of the Eastern Empire in the middle of the Sixth Century. (3) The _Variae Epistolae_ of Cassiodorus, the composition of which ranges from about 504 to 540. The first of these authorities relates to the Eastern and Western Empires, the second to the Eastern alone, the third to the Western Empire as represented by the Ostrogothic Kingdom founded by Theodoric. Much light is also thrown on the subject by the Codes of Theodosius and Justinian. Godefroy's Commentary on the Theodosian Code, and Bethmann Hollweg's 'Gerichtsverfassung des sinkenden Roemischen Reichs,' are the chief modern works which have treated of the subject. [Sidenote: The Officium as described in the Notitia.]