Strez from an expansion to the south. In relation to an anti-Bogomil council in 1211, Strez is referred to as a sebastokrator. The title was either conferred to him by Boril as part of their agreement in 1209, or was awarded to Strez by Kaloyan during his rule. In any case, Boril certainly recognized Strez's right to that appellation. There are signs that Strez divided his possessions into administrative units, each headed by a sebastos. In 1212, Strez was powerful enough to be considered one of the Latin Empire's chief adversaries, along with Boril, Michael and Nicaean emperor Theodore I Laskaris, by Henry himself. Anti-Serbian campaign and death After a series of military failures against the Latins, Boril made peace with Henry in 1213, cemented through two royal marriages. As Boril's vassal, Strez joined the Bulgarian–Latin union, the short-term goal of which was a double invasion of Serbia. In 1214, the forces of Boril and Henry attacked Serbia from the east, while Strez's army, deemed in contemporary sources to be "countless", penetrated Serbian territory from the south and reached the Polog. Facing a major invasion on two fronts, the Serbs were quick to ask for peace. After Stefan's envoys to Strez failed, he sent his brother, archbishop Sava (canonized as Saint Sava) to Strez's camp. Even though Sava's diplomacy was of no effect either, Strez died the night after Sava's departure. Serbian sources present the death of Strez as a miracle, Strez being stabbed by an angel, though he was possibly murdered in a plot orchestrated by Sava. Historian John V. A. Fine theorizes that Sava may have found supporters among Strez's nobles, some of whom had turned against him and organized his murder, only to defect to Serbia immediately afterwards. According to the hagiography of Saint Sava, in his dying words Strez claimed he was stabbed by a young soldier on the order of Sava. While Strez's death meant an end to the Latin–Bulgarian campaign, Stefan did not undertake a campaign into Macedonia due to the proximity of the coalition troops, which had halted at Niš. In 1217, all of Strez's territory was under the Epirote rule of Theodore Komnenos Doukas, though Boril may have controlled some or all of it in the meantime. The Serbs failed to take advantage of Strez's death as far as they did not manage to acquire any of his former domains. Assessment and