Sebastokrator Strez

Strez was a nobleman of the Asen dynasty who ruled independently between 1211 and 1214. He received from the Bulgarian tsar Boril the title of "sebastokrator", which ranked second in importance after autokrator, or sovereign tsar. 

In 1207, after Tsar Kaloyan's death and Boril's accession to the throne, Strez fled to Serbia, where he sought refuge at the court of župan Stefan Nemanja. It is thought that he may have feared being killed by Boril as a potential rival for the throne, or that he actually was a rival, but ultimately his brother Boril prevailed in the struggle for power. Strez received support from Grand Župan Stefan Nemanja, who supplied him with troops. With their help, Strez successfully conquered part of Macedonia. He consolidated his position by occupying the impregnable fortress of Prosek near the River Vardar, where Dobromir Chrysos had ruled before him. Strez proclaimed himself an independent ruler and strengthened his control in the region. His lands extended from the River Struma to Ohrid and, according to some views, also included the regions of Devol and Kastoria. 

Around 1211, although the details of the sequence remain unclear, Boril and Strez entered into an alliance. Strez recognised Tsar Boril's supremacy and received the title of sebastokrator in return. In practice, however, Strez retained a substantial degree of autonomy. That same year, with Boril's military support, Strez attacked the Kingdom of Thessaloniki. Nevertheless, in the battle on the Bitola plain he was defeated by the Latin knights. In 2013 he was killed.