Byzantium bordered to the North on the mighty Bulgarian state. The Empire had in its face a centuries old powerful military enemy. To the time when the Byzantine capital was taken by the crusaders , on the Bulgarian throne reigned king Kaloyan (1197-1207). By the newly established situation Kaloyan regarded as reasonable the creation of good neighborly relations with the Latins and sent a letter to Baldwin of Flanders with an offer for a peace. But the Emperor rejected it and made unfounded territorial demands to Bulgaria under the pretext that the lands belonged to the ex-Byzantine Empire.
It came gradually to a military conflict with a culminating point in the battle by Odrin. On the 14 of April , 1205 under the walls of the town there was waged a bloody fighting. King Kaloyan used old military tricks - captivated the heavy armed crusade forces in a swampy country side and stroke a hard blow. The crusaders were routed and Emperor Baldwin of Flanders caught and died in the prison of the Bulgarian capital Tarnovo.
The Crusade troops were considered as an invincible army until that moment. They were heavy armed covered with chainmails and riding horses, which had also preventive shields. But the myth of their power disappeared in the battle by Odrin against king Kaloyan. The army, which the Bulgarian king was light armed and with a fast cavalry. King Kaloyan as also the most Bulgarian kings didn't miss a strategical sense of military actions.
And so under pretext that they would liberate the Christian lands from the faithlesses, the crusaders fourth march in turn took by storm the capital of the Orthodox Byzantine Empire. The aim was a bigger influence among the Christian peoples. Regularly or not the invincible until then knights were routed by the Bulgarian king Kaloyan . With that his name remains in the history for ever.








