CUMANS DURING THE REIGN OF BORIL, 1207–1218

As we saw in the previous chapter, Kaloyan was succeeded by his nephew Boril, the son of the sister of the three brothers. In an attempt to legitimate his rule, Boril married Kaloyan's Cuman wife, but his reign was never regarded as legitimate. Asen's sons John and Alexander fled to the Cumans, then to the Russians. John was the later Ivan Asen II, who returned from exile in 1218 and became the best-known ruler of the Second Bulgarian Empire. According to the common view, ‘the land of the Russians’ was the Principality of Galič, but P. Pavlov has successfully shown that the brothers in fact fled to Kiev. Ivan Asen was to remain in Kievan Rus' as a political exile for a long time, during which he was planning to secure Russian and Cuman assistance to take back the Bulgarian throne as his paternal heritage.

Boril was considered a usurper, and internal anarchy increased throughout his reign (1208–18). Centripetal powers strengthened and the decade of his rule was characterised by the feuds of different boyar groups. Several pretenders to the throne had arisen, among whom Boril's brother Strez and Kaloyan's nephew Aleksi Slav were the most powerful. Strez was supported by the Serbian Grand Župan Stefan Nemanja II, who gave him Prosek in western Bulgaria. Aleksi Slav was the feudal lord of the Rodope region south of Philippoupolis (Plovdiv).