Theophanes the Confessor in the context of "Siege of Constantinople (674–678)"

The Seven Slavic tribes (Bulgarian: Седемте славянски племена, romanized: Sedemte slavyanski plemena), or the Seven clans (Bulgarian: Седемте рода, romanized: Sedemte roda) were a union of Slavic tribes in the Danubian Plain, that was established around the middle of the 7th century and took part in the formation of the First Bulgarian Empire together with the Bulgars in 680−681.

Since its establishment, it faced attacks from the Byzantine Empire. The Bulgars crossed the Danube and in the 670s they concluded an alliance with the Slavic Union. Theophanes writes that the Bulgars became masters of the Slavs. The Slavic Union recognized the sovereignty of Khan Asparuh and together, in the spring of 681, they won a major victory over the Byzantines.

Ongal (or Onglos) was the first settlement of the Asparuh Bulgars after their settlement on the Lower Danube in the second half of the 7th century.

The Ongal began as a fortified camp with an area of 48 km². The location of the Ongal is described by Byzantine chroniclers Theophanes the Confessor and Nikephoros I of Constantinople.

The paradynasteuōn (Greek: παραδυναστεύων, "the one who rules beside") was a term used, especially in the Byzantine Empire, to designate a ruler's favorite, often raised to the position of chief minister. Probably deriving from Thucydides, it was used in the later Roman Empire for people with great authority. It was not an official title or position, but the term was extensively used by chroniclers such as Theophanes the Confessor or Theophanes Continuatus to designate an emperor's closest aide and chief minister. It gained greater currency during the Komnenian period and continued to be used by historians of the Palaiologan period, although the more technical term of mesazōn ("mediator"), which eventually came to correspond to an actual office, had largely replaced it.

The first plague pandemic was the first historically recorded Old World pandemic of plague, the contagious disease caused by the bacterium Yersinia pestis. Also called the early medieval pandemic, it began with the Plague of Justinian in 541 and continued until 750 or 767. At least fifteen to eighteen major waves of plague following the Justinianic plague have been identified from historical records. The pandemic affected the Mediterranean Basin most severely and most frequently, but also infected the Near East and Northern Europe, and potentially East Asia as well. The Roman emperor Justinian I's name is sometimes applied to the whole series of plague epidemics in late antiquity.

The pandemic is best known from its first and last outbreaks: the Justinianic Plague of 541–549, described by the contemporary Roman historian Procopius, and the late 8th century plague of Naples described by Neapolitan historian John the Deacon in the following century (distinct from the Naples Plague of the 17th century, during the second plague pandemic). Other accounts from contemporaries of the pandemic are included in the texts of Evagrius Scholasticus, John of Ephesus, Gregory of Tours, Paul the Deacon, and Theophanes the Confessor; most seem to have believed plague was a divine punishment for human misdeeds.

Theophanes Continuatus (Greek: συνεχισταί Θεοφάνους) or Scriptores post Theophanem (Οἱ μετὰ Θεοφάνην, "those after Theophanes") is the Latin name commonly applied to a collection of historical writings preserved in the 11th-century Vat. gr. 167 manuscript. Its name derives from its role as the continuation, covering the years 813–961, of the Chronicle of Theophanes the Confessor, which reaches from 285 to 813. The manuscript consists of four distinct works, in style and form very unlike the annalistic approach of Theophanes.

The first work, of four books consists of a series of biographies of the emperors reigning from 813 to 867 (from Leo the Armenian to Michael III). As they were commissioned by Emperor Constantine VII (r. 913–959), they reflect the point of view of the reigning Macedonian dynasty. The unknown author probably used the same sources as Genesios. The second work is known as the Vita Basilii (Latin for "Life of Basil"), a biography of Basil I the Macedonian (r. 867–886) written by his grandson Constantine VII probably around 950. The work is essentially a panegyric, praising Basil and his reign while vilifying his predecessor, Michael III. The third work is a history of the years 886–948, in form and content very close to the history of Symeon Logothetes, and the final section continues it until 961. It was probably written by Theodore Daphnopates, shortly before 963.

Theodore or Theodoros Rshtuni (Old Armenian: Թէոդորոս Ռշտունի, romanized: T῾ēodoros Ṙštuni, Armenian pronunciation: [tʰɛodoɾos ərəʃtuni]; AD 590–655 or 656), equated with Pasagnathes (Πασαγνάθης), the "patrikios of the Armenians" from the chronicle of Theophanes the Confessor, was an Armenian nakharar (magnate), famous for resisting the first Arab invasions of Armenia. After the previous ishkhan (prince) David Saharuni was overthrown by other nakharars in 638 or 640, Theodore Rshtuni became the leading prince of Byzantine Armenia under the same title as his predecessor, "Prince of Armenia" (ishkhan hayots’).