Serbia, Europe, Historical Profile (1922), #005-The Princes of Zeta and the First Serb Kingdom
Towards the end of the 9th century the political centre of the Serbs was transferred to Zcta (or Zenta)The prince (sometimes called king) of Zeta, Yovan Vladimir, tried to stop the triumphal March of the Bulgarian Tsar Samuel through the Serb provinces, but in 9S9 was defeated, made prisoner and sent to Samuel's capital, Prespa.
The historical fact that Vladimir married Kossara, the daughter of Samuel, and was sent back to Zeta as reigning prince under the Bulgarian suzerainty, forms the subject of the first Serb novel, Vladimir and Kossara, as early as the 13th century. Vladimir, who seems to have been a noble-minded man, was murdered by Samuel's successor, the usurper Tsar Vladislav (1015). By the Christians of both churches in Albania he is to this day venerated as a saint. But after the death of Samuel the Bulgarian power rapidly lost the Serb provinces, which, to get rid of the Bulgarians, again acknowledged the Greek overlordsliip.
About 1042, however, Prince Voislav of Travuniva (Trebinje), cousin of the assassinated Vladimir of Zeta, started a successful insurrection against the Greeks, and united under his own rule Travuniva, Zahumlye (the modern Herzegovina) and Zeta. His son Michael Voislavich annexed the important Zhupaniya of Rashka (Rascia or Rassia), and in 1077 was addressed as king (rex) in a letter from Pope Gregory VII. His son Bodin enlarged the first Serb kingdom by annexing territories which up to that time were under direct Greek rule.
After Bodin's death the civil wars between his sons and relatives materially weakened the kingdom. Bosnia reclaimed her own independence; so did Rashka, whose Grand Zhupans came forward as leaders of the Serb national policy, which aimed at freedom from Greek suzerainty and the union of all the Serb Zhupaniyas into one kingdom under one king. The task was difficult enough, as the Byzantine empire, then under the reign of the energetic Manuel Comnenus, regained much of its lost influence. About the middle of the 12th century all the Serb Zhupaniyas were acknowledging the suzerainty of the Byzantine emperors.