Knowledge of Byzantine history comes from a variety of sources, including the writings of Church Fathers, proceedings of the regional and Ecumenical Synods, imperial documents, diplomatic records, and biographies of saints, known as hagiographies. The main sources used in the preparation of this study are:
1. The Kletorologion (Κλητορολόγιον): This text was written at the close of the ninth century by Philotheos, a high official in the service of the empire, an imperial bodyguard (protospatharios), and Master of the Feast (architriklinos). It offers a description of many imperial ranks, including an organizational chart for offices that were active at the time.
Of the major administrative ranks, Philotheos distinguishes between two categories: (a) honorary distinctions granted by the emperor with special diplomas or with medals and badges and (b) true ranks for imperial officials granted by decree. Philotheos identifies fourteen genuine ranks, with that of Magister (Master of the Offices) as the highest. He also lists three additional categories reserved for men of the imperial family (Kouropalates, Caesar, and Nobelissimos) and a solitary female rank, Zoste Patricia, granted to imperial women. There were a further eight titles reserved for eunuchs.
2. Taktikon (Τάκτικον): Is a document that lists imperial offices dating to the reign of Emperor Michael (842-867 ce) and his mother, St. Theodora, who was responsible for the second restoration of icons in 843. This list is also known as the Uspensky Taktikon, after it was discovered and published by the Russian historian Theodore Uspensky. The word taktikon is derived from τάξις (taxis), meaning a social arrangement or ceremony. Thus a taktikon meant a list of ceremonies. It is an abridged record of various military and political officials as well as officiating clergy, arranged by seniority. Titles of officials are listed according to their rank. This is a manual for ceremonies to be used by the Great Master of Ceremonies in the Palace, who was responsible for the list.
3. Works of Constantine VII Porphyrogennetos (913-959). First, De Ceremoniis aulae byzantinae (“The Ceremonies of the Byzantine Imperial Court”), written for the benefit of the emperor’s son, details the emperor’s ritualized public functions in religious ceremonies. It also provides practical advice in the art of diplomacy and the management of imperial officials. It includes descriptions of sacramental rites, imperial coronations and burials, and additional ecclesiastical ceremonies, receptions, and the welcoming of foreign ambassadors. Second, the De Thematibus is a historical and geographical survey of the provinces of the Empire, based upon earlier geographical works of the fifth and sixth centuries. Third, De Administrando Imperio describes the nations and people with whom the Byzantine Empire had diplomatic, political, economic, and trade relations.
4. Taktikon Concerning the Offices of the Palace of Constantinople and the Offices of the Great Church: This book was most likely written during the reign of Emperor John VII Katakouzenos (1347-1354 ce). The volume supplies us with information about the late-Byzantine period, describing in detail the coronation rites and imperial funerals. In addition, it outlines, according to rank, the list of ecclesiastical hierarchs and political officials with their duties and the certificates and diplomas of the various ranks bestowed.
5. Ecclesiastical Histories: Eusebius of Caesarea (260-340 ce) was the first Christian to apply the genre of the Greco-Roman historical chronicle to the history of the Christian community. His Ecclesiastical History records the history of the Church from its beginnings until 303, the time of the Great Persecution under Emperor Diocletian (284-304 ce), and then continues to the years under Constantine the Great (313-337 ce). Like all ancient histories, it is apologetic rather than objective and presents the reign of Constantine as the culmination of the divine script for human history. In the following century, a Constantinopolitan attorney by the name of Socrates (380-450 ce) composed his own Ecclesiastical History covering the years 305-439 ce. A contemporary, Sozomen, also wrote a treatise by the same title, which consists of nine books covering the years 324 until 425.
Throughout the Byzantine Empire, additional authors took up the genre of the chronicle, with some emphasizing political and others emphasizing ecclesiastical concerns. The Chronographia of Michael Psellus (c. 1019-1079) is worth noting because of Michael’s depth of learning and unprecedented willingness to embrace the pre-Christian Hellenistic origins of the Byzantine world as well as his fearlessness in critiquing public officials still in office.
6. Imperial Law Codes: By the time of the legalization of Christianity in 313 ce, the Roman Kingdom/Republic/Empire had been in existence for at least a thousand years. Over that time, an enormous amount of legislative work had been produced and much of it was overlapping or contradictory. The Roman emperor Theodosius II (408-450 ce) commissioned experts to produce a comprehensive codex of Roman law. Known as the Theodosian Code, the text contains 16 books and each is divided into subdivisions (tituli), dealing with various topics. The Theodosian Code describes various imperial offices as well as military, administrative, and religious positions. Royal decrees issued after the publication of the codex were called Novellae. As important as the Theodosian Code is, it pales in comparision to the massive legal undertaking commissioned by the Roman Emperor Justinian I (527-565 ce). All modern jurisprudence in the Western world is derivative of the Justinianic Code. As an indication of the gradual transformation of the Byzantine Empire, it is worth noting that the codification of earlier Roman laws is written in Latin, whereas the new laws (Novellae) issued by Justinian are composed in Greek. It is further noteworthy that Justinian equated Church law (i.e., the canons of the Ecumenical Councils) with imperial law.
7. Notitia Dignitatum: This book, likely stemming from the fifth century ce, provides an official list of civilian and military offices for both halves of the later Roman Empire. It is significant primarily because it shows the changing shape of the empire in the transition from the Roman to the Byzantine world.
8. Canon Law: In addition to the legislative decrees of the Ecumenical Councils, there were additional canons issued by regional councils or extracted from the writings of the Church fathers. Beginning in the middle Byzantine period, Church lawyers began to assemble and comment upon these texts, especially in those areas where the laws seemed to be contradictory. A modern edition of these medieval commentaries was prepared by G. Ralles and H. Potles entitled, The Constitution of the Divine and Sacred Canons. This material is relevant to the study of the Byzantine offices because the middle and late Byzantine commentaries on canon law frequently contain information about personalities within the imperial administration and thus give further insight to the intersection between Church and state.