Bulgar–Serb War (839–842) in the context of Bulgarian–Serbian Wars (medieval)

The Belojević clan (Serbian Cyrillic: Белојевић), colloquially Travunian dynasty, was a local Slavic ruling clan from region surrounding Trebinje, a center of an early Slavic polity, Travunia. The clan was in vassal relations with the first Serbian Principality's ruling Vlastimirović's, but constantly strived for independence starting with the clan's progenitor Beloje, who sought to free himself of Serbian rule. Beloje was mentioned as the župan of Travunia in the chapter on the Serbs in De Administrando Imperio (DAI) of Byzantine Emperor Constantine VII (r. 945–959). Prince Vlastimir (r. 836–851) married his daughter to Beloje's son Krajina, and elevated him to the rank of archon, sometime prior the Bulgar–Serb War (839–842). Krajina's descendants were entitled to rule the region comprising the hinterland of Dubrovnik and Boka Kotorska, with seat at Trebinje, still under Serbian suzerainty. The clan is later mentioned in the semi-mythical Chronicle of the Priest of Duklja, which mentioned that a descendant of Hvalimir, Dragomir, ruled Travunia in the second half of the 10th century, his brother Petrislav ruling Duklja and his son Stefan Vojislav later ruling Duklja and founding the Vojislavljević dynasty.

Beloje (Serbian Cyrillic: Белоје; Greek: Βελάης; fl. 839), was a local Slavic chieftain from the region surrounding Trebinje, who ruled the area with a title of župan, sometime in the first half of the 9th century. Travunia was a polity centered in Trebinje (now in southern Bosnia and Herzegovina), and at the time subject to the Principality of Serbia. Mentioned in De Administrando Imperio (DAI) of Byzantine Emperor Constantine VII (r. 945–959), Beloje was a contemporary of Serbian ruler Vlastimir (r. 836–851). It is unknown how he came to the position; it might have been through the primogeniture principles, however, there is no definite answer. Vlastimir married his daughter to Beloje's son Krajina, and "desiring to ennoble his son-in-law", elevated his rank to archon (prince) and made him independent. Travunia was thus elevated from a župa into an archonty (principality), practically independent, while Vlastimir oversaw his son-in-law. T. Živković theorized that Beloje sought to free himself of Serbian rule, and that Vlastimir prevented this through a political marriage between the two families, possibly prior to the Bulgar–Serb War (839–842). Krajina's descendants were entitled the rule of Travunia under Serbian suzerainty.

There is a hypothesis that the legendary king Pavlimir Belo (or Belimir) mentioned in the Chronicle of the Priest of Duklja (CPD) was supposedly based on Beloje. The CPD is a primary source dating to ca. 1300–10 largely discredited in historiography (events in the Early Middle Ages deemed useless). The CPD mentions this individual, Belo, as being born as Pavlimir, receiving his nickname from his relatives and other Romans from bello, "because he very much loved war". The legend of Pavlimir-Belo continues with his stint at Syrmia, where he defeated the Syrmians and Hungarians, and his defeat of Rascian župan Ljutomir. Belo is mentioned in the CPD as a Rascian župan, while DAI mentions Beloje as a Travunian župan. N. Banašević noted that while the two names were similar, they were not identical.