Dušan's Code in the context of "The Proclamation of Dušan's Law Codex"

The Byzantine calendar, also called the Roman calendar, the Creation Era of Constantinople or the Era of the World (Ancient Greek: Ἔτη Γενέσεως Κόσμου κατὰ Ῥωμαίους, also Ἔτος Κτίσεως Κόσμου or Ἔτος Κόσμου; lit. 'Roman year since the creation of the universe', abbreviated as ε.Κ.), was the calendar used by the Eastern Orthodox Church from c. 691 to 1728 in the Ecumenical Patriarchate. It was also the official calendar of the Byzantine Empire from 988 to 1453 and it was used in Russia from c. 988 to 1700. This calendar was used also in other areas of the Byzantine commonwealth such as in Serbia — where it is found in old Serbian legal documents such as Dušan's Code, thus being referred as the "Serbian Calendar" and today still used in the Republic of Georgia alongside Old Style and New Style calendar.

The calendar was based on the Julian calendar, except that the year started on 1 September and the year number used an Anno Mundi epoch derived from the Septuagint version of the Bible. It placed the date of creation at 5509 years before the incarnation of Jesus, and was characterized by a certain tendency that had already been a tradition among Jews and early Christians to number the years from the calculated foundation of the world (Latin: Annus Mundi or Ab Origine Mundi— "AM"). Its Year One, marking the assumed date of creation, was September 1, 5509 BC, to August 31, 5508 BC. This would make the current year (AD 2025) 7534 (7533 before September 1).

The sebri (Serbian Cyrillic: себри) was the lower-half social class, commoners, of the medieval Serbian state. The status of the groups comprising the class was regulated in medieval code of laws, such as Dušan's Code (1349). It included several groups, mainly divided into:

• The meropsi (меропси) or merophe (меропхе), dependent farmers. Other terms included zemljanin ("earthen [man]", from zemlja, "land"), Srbljin (from the Serb ethnonym), or zemljani ljudi ("earthen folk"). They served either the ruler, the church, or nobility. Medieval sources allows for understanding the legal position of the church's meropsi, while that of the ruler's and nobility's meropsi is deemed insufficient. The fact that there were three groups implies that their status was not identical, however, it has been established that their status did essentially not differ.
• The vlasi (власи) or pastiri (пастири), dependent shepherds. The multitude and likely prevalence of Vlachs (Romanized remnants; see Vlachs in medieval Serbia) among the shepherds made the term "Vlachs" a synonym for shepherds, similarly as the term Srbljin was sporadically used for farmers. The status of the vlasi was basically equal to the meropsi.
• The otroci (отроци), a type of medieval slaves. This group was closest to having complete deprivation of rights, similar to slaves (robovi), although this has for long and persistently been disputed in scholarship. The lord could free his otroci from that status, which points to similarity with slave status.
• The dependent (or rural) craftsmen and sokalnici (сокалници). The craftsmen and sokalnici had a special status, which is unclarified from available sources.
• Partially also the rural clergy.