An attempt has been made in the article in order to summarize the foreign policy of Bulgaria during the 13th century. The author's observations are based both on individual sources and on a number of studies (above all on Bulgarian medieval studies). It is stressed that, once the Latins had conquered Constantinople in 1204, the Bulgarian Kingdom emerged on the historical scene as the main support and defender of the Balkan Orthodox world. It played, having been the main ally of Nicaea, an important role in restoring of the Byzantine Empire in 1261. The Tatar Golden Horde was an extremely negative factor for the foreign policy of Bulgaria after 1242-1243. Special attention is devoted to rich Bulgarian-Serbian relations. The animosity between the two states was connected to the expansion of the Serbian Kingdom during the second half of the century in Macedonia, and in the areas of Belgrade, Braničevo and Vidin. A considerable place in the Bulgarian foreign policy was attributed to the relations with the Roman Church and the Catholic states (the Hungarian Kingdom, the Latin Empire in Constantinople, the Kingdom of Naples, etc), as well as with the merchant republics of Ragusa, Venice and Genoa.
