Tsar Boril

Boril was tsar of Bulgaria from 1207 to 1218. He ascended the throne after a civil war against rival claimants to the crown, Alexius Slav and his brother Strez. Boril legitimised his rule by marrying the murdered tsar’s widow.

Boril’s reign was associated with a series of failures. He continued the policy of his predecessors Peter, Asen and Kaloyan, pursuing an aggressive foreign policy. His military campaigns were often judged unsuccessful and disastrous, weakening the Bulgarian army and exhausting the country economically.

In 1208, Boril led an army into eastern Thrace, where he confronted Latin forces. The Battle of Boruy in June 1208 ended in a Latin defeat, and the Latins withdrew towards Plovdiv. The subsequent Battle of Plovdiv in July 1208, however, ended in Boril’s defeat. This setback decided Thrace’s fate, as the Latins took control of the region. Alexius Slav, a claimant to the throne, recognised Latin rule and became a vassal and later a son-in-law of the Latin emperor Henry.

After the defeat at Plovdiv and the establishment of Latin rule in Thrace, Boril remained tsar until 1218, but his reign was disrupted by setbacks and losses along the external frontiers. His rule was characterised by difficulties and is remembered as one of the weaker reigns of the Second Bulgarian Empire.

The continuing war between Boril and the Latin emperor Henry, together with subsequent events, represents a complex period in medieval Bulgarian history.

After the defeat on the Bitola plain, or Pelagonia, and Boril’s capture of Melnik, the combined forces of the Latins and Despot Slav inflicted a heavy defeat on the Bulgarians. This led to a change in relations between Boril and Henry. The emperor’s decision to marry Maria, a daughter of the Bulgarian ruler Kaloyan, was intended to restore a balance and stabilise relations between the two sides.

In 1213, Boril suppressed a revolt by Cuman leaders in the Vidin region with the support of Hungarian troops sent by King Andrew II. In return for this help, he ceded the Belgrade and Braničevo regions to the Hungarians.

In 1214, Boril initiated the formation of a powerful coalition involving the Latin Empire, Strez and the Epirote despot Michael I Komnenos Doukas Angelos. The coalition took military action against the Serbian ruler Stefan and besieged Niš. However, the Bulgarians attacked the Latins in their camp, infighting broke out and the attack plan failed. Boril’s ally Strez died unexpectedly after a visit by the Serbian Church leader Sava. Michael Komnenos successfully captured Skadar, or Shkodër, but he too died. These events weakened Boril’s influence in the region and undermined his plans to unite the neighbouring territories.