Diplomacy

The restored Bulgarian state entered international politics with an ambitious ideological program. Its rulers sought not merely territorial independence from Byzantium but recognition of a sovereign Bulgarian monarchy and church. The title associated especially with Kaloyan, ruler of Bulgaria and Vlachia, reflected authority over Moesia, parts of Thrace and Macedonia, and territories north of the Danube then known as Vlachia. Yet the new monarchy had inherited neither uncontested legitimacy nor secure frontiers. Its diplomacy therefore combined claims drawn from the earlier Bulgarian imperial tradition with pragmatic appeals to powers outside the Orthodox Byzantine order.

Kaloyan’s relations with the papacy were the clearest expression of this search for recognition. He doubted whether a crown bestowed by the archbishop of Tarnovo alone possessed sufficient international legitimacy and consequently turned to Rome. Papal recognition and the royal crown received in 1204 strengthened his standing at the moment when the Fourth Crusade destroyed Byzantine rule in Constantinople and created the Latin Empire. Kaloyan could now present himself as a ruler recognized beyond the Balkans while exploiting the political vacuum left by the Byzantine collapse. His conquests in Macedonia and Thrace were accompanied by ecclesiastical measures: Greek bishops considered unreliable were removed and replaced by Slavic clergy, while suspect inhabitants were transferred to the Danubian lands. Thus diplomacy, conquest and church policy worked together to consolidate Bulgarian sovereignty.

Relations with the Latin Empire nevertheless showed that recognition did not create permanent alignment. Bulgaria and the crusader regime became rivals over the Byzantine inheritance, and Kaloyan’s successors had to maneuver among the Latins, Hungary and the Greek successor states. Under Boril, weakened by internal rivals and separatist principalities, Bulgaria entered close relations with Hungary around 1213 and received Hungarian help against a rebellion at Vidin. Boril also maintained an alliance with the Latin emperor Henry, while a projected engagement in 1214 between Boril’s daughter and the future Béla IV was intended to reinforce the Hungarian connection. These arrangements restricted the freedom of separatists such as Alexios Slav, who responded by moving toward Epiros and sealing his new association through marriage in 1216. Dynastic marriage had already become one of the principal instruments by which Bulgarian rulers and regional lords changed diplomatic camps.

Ivan Asen II’s accession in 1218 transformed Bulgaria’s position. When the returning Hungarian king Andrew II reached the Bulgarian frontier late that year, Ivan Asen detained him and permitted him to continue only after he accepted a marriage between the Bulgarian ruler and his daughter Maria. The wedding took place early in 1221. The marriage was not simply a family compact: Beograd and Branichevo, disputed Danubian strongholds, apparently passed to Ivan Asen as Maria’s dowry. In this way dynastic diplomacy achieved what war might have made costly, temporarily restoring Bulgarian authority in a region contested with Hungary throughout the thirteenth century.

Ivan Asen II initially observed the rivalry among the Latin Empire, Epiros, Nicaea and the Bulgarian state from a strategically advantageous position. Epiros had become the most vigorous Balkan power under Theodore, but its defeat by Ivan Asen in 1230 destroyed its imperial predominance. Bulgarian power then extended into Greek, Albanian and Serbian lands, while another dynastic bond linked Ivan Asen’s family to the Serbian ruler Stefan Vladislav. The victory did more than enlarge Bulgaria: it altered the balance among the successor states competing for Constantinople and enabled Tarnovo to aspire to leadership in the Orthodox world. The older formula including Vlachia receded as the monarchy’s political ideology turned more directly toward Bulgarian hegemony among Orthodox states.

Commercial diplomacy complemented this expansion. In 1230 Ivan Asen II granted Dubrovnik a charter permitting Ragusan merchants to trade freely in Bulgarian cities, including Beograd and Branichevo. The charter demonstrated both the geographical reach of Bulgarian claims and the crown’s willingness to use privileges for foreign merchants to stimulate exchange and bind distant urban communities to the monarchy. Access to Adriatic traders widened Bulgaria’s diplomatic horizon beyond its immediate land frontiers. Commercial agreements were not separate from high politics: they advertised control of contested provinces, encouraged customs revenue and offered foreign communities an interest in the stability of Bulgarian rule.

The struggle for Constantinople soon forced Ivan Asen to reassess his partners. After John of Brienne assumed power in the Latin capital in 1231, Bulgaria opened negotiations with Nicaea and in 1232 aligned with it against the Latin Empire. Hungary, a Catholic protector of the Latin regime, reacted by taking Beograd and Branichevo and besieging Vidin in 1232; although a Bulgarian relief army was defeated, Vidin itself held out. In 1234 Ivan Asen’s daughter was betrothed to the Nicaean heir, and in 1235 the Bulgarian and Nicaean courts met at Gallipoli. The settlement included important ecclesiastical concessions: Tarnovo abandoned jurisdictional claims over Thessaloniki, Mount Athos and eastern Thrace, and recognized the Nicaean patriarch as ecumenical patriarch. The marriage alliance and church agreement made possible joint operations against Constantinople.

Yet Ivan Asen’s diplomacy remained flexible rather than doctrinaire. During the siege of Constantinople in 1235–1236, he recognized that a Nicaean victory would restore a powerful Greek empire in the city and might be more dangerous to Bulgaria than the weak Latin regime. He therefore broke the alliance, sought the return of his daughter and recruited Cuman forces against Nicaea. By the end of his reign he again improved relations with Hungary and, indirectly, with the Latin Empire. The emergence of the Tatars supplied a compelling reason: the destruction of the Cuman state in 1238–1239 and the conquest of Kiev in 1240 placed a formidable steppe power on the borders of both Bulgaria and Hungary. A Bulgarian envoy was well received by King Béla in the first months of 1240, indicating movement toward common defense against a danger greater than their Danubian disputes.

After Ivan Asen’s death, the diplomatic system became harder to control. Minority rulers, quarrelling regents and provincial boyars weakened the personal bonds that had held the realm together, while the Mongol-Tatar invasions of 1241–1242 removed the friendly Cuman buffer and exposed Bulgaria to the Golden Horde. Successive governments attempted to prevent simultaneous wars on several fronts. In 1255 Tsar Michael married a granddaughter of the Hungarian king, renounced claims to Beograd and Branichevo and secured an alliance with Hungary so that Bulgarian forces could concentrate on Nicaea and Macedonia. After costly campaigns, Nicaea recovered the disputed territories by July 1256; peace was mediated by Michael’s new father-in-law, Rostislav of Mačva. Marriage diplomacy had bought strategic freedom, but it also drew Hungarian-connected dynasts directly into Bulgarian succession politics.

The murder of Michael and the rapid fall of Koloman in 1256–1257 exposed this danger. Koloman forcibly married Michael’s widow, Rostislav’s daughter, to strengthen his own claim, but failed to consolidate power. Rostislav invaded, later established himself at Vidin and, with Hungarian recognition, assumed the title of tsar of Bulgaria. Another claimant, Mico, appeared in the southeast. Under Constantine Tih, Tarnovo therefore had to balance Nicaea, Hungary and rival Bulgarian centers. An alliance with Nicaea was sealed by Constantine’s marriage to Irene in 1258 and confirmed when George Akropolites visited Tarnovo around January 1260. The resulting peace lasted from 1258 to 1262 and allowed Constantine to concentrate on the Hungarian-supported threat in the northwest.

The recovery of Constantinople by Michael VIII Palaiologos in 1261 changed the relationship. Nicaea again became Byzantium, while the blinding of John IV Laskaris, a relative of Constantine’s wife Irene, sharpened hostility toward Michael VIII. War in 1262–1263 cost Bulgaria fortresses in western Thrace and along the Black Sea. At the same time Vidin passed under the Hungarian protection of Jacob Svetoslav, who accepted Hungarian suzerainty for Vidin and his other territories. Faced with stronger enemies to the south and northwest, Constantine accepted western losses and sought peace with Hungary so that he could concentrate on Byzantium. The episode illustrates a recurring Bulgarian dilemma: diplomatic concentration on one frontier often required recognition of damaging faits accomplis on another.

Steppe diplomacy now became unavoidable. Constantine appealed to his Tatar overlords against Byzantium, but the Golden Horde was divided. Khan Berke had offered some protection before his death in 1265; his successor Möngke Temür exercised weaker control, while Nogai emerged as an increasingly autonomous power near Bulgaria. Byzantium itself cultivated steppe alliances and, after Constantine raided Thrace around 1271, called on Nogai, whose forces crossed the Danube and devastated Bulgaria. Encircled by Byzantium, Hungary and Nogai, Constantine made peace but joined Charles of Anjou’s anti-Byzantine coalition in 1272 or 1273 when the opportunity arose. This western alignment offered a diplomatic counterweight, yet Bulgaria’s exposed position prevented effective action. By the reign of George I Terter, Nogai’s predominance had produced the period of greatest Tatar interference, from about 1280 until Nogai’s death in 1299.

Byzantium repeatedly used dynastic claimants and aristocratic exiles as instruments of intervention. Its attempt to install Ivan Asen III at Tarnovo failed when Ivaylo defeated invading Byzantine armies and the imperial candidate fled. George I Terter then sought accommodation. After the Sicilian Vespers removed Charles of Anjou as an effective counterweight, Bulgaria lacked the strength to recover Thrace or the Black Sea coast without assistance. In 1284 Andronikos II recognized George as tsar of Bulgaria and granted him the Byzantine court title of despot. The treaty represented mutual realism: Byzantium abandoned an unsuccessful candidate, while Bulgaria recognized that peace was preferable to an unwinnable attempt to recover disputed lands.

A more successful combination of war, peace and commerce appeared under Theodore Svetoslav. Bulgarian victory over the Byzantines at the Skafida River in 1304 was followed, before 2 April 1307, by a durable peace that legalized Bulgarian gains made between 1304 and 1307. The agreement allowed Byzantium to turn against the Catalan danger and schemes to restore the Latin Empire, while Bulgaria stabilized its international and domestic position. Theodore’s marriage to Theodora Palaiologina helped sustain the settlement and provided a channel for influence at the Byzantine court; at her request, her father Michael IX ordered in 1318 that properties taken from the Bulgarian monastery of Zographou be restored. The recovered Black Sea ports expanded trade carried in Venetian and Genoese ships, chiefly exporting agricultural produce and importing luxury goods. Increased commerce was accompanied by much larger issues of Bulgarian coinage and strengthened the monarchy’s economic basis.

The rise of Serbia posed a different challenge. Bulgarian influence in Macedonia had already receded while Serbian expansion advanced southward. Michael III Shishman Asen attempted to confront this altered balance, but the Bulgarian defeat by Serbia at Velbazhd on 28 July 1330 ended with his death and enabled Serbia to support Ivan Stefan’s accession. Ivan Stefan was soon expelled by an anti-Serbian revolt, and Ivan Alexander became tsar in 1331. His initial victory over Andronikos III at Rusokastro on 18 July 1331 restored several southeastern towns and checked Byzantine pressure. He then secured his western frontier through the marriage of his sister Elena to Stefan Dušan on 19 April 1332. The marriage inaugurated a Bulgarian-Serbian peace that endured, but it also left Dušan free to expand through Macedonia while Bulgaria turned once more toward Thrace.

During the Byzantine civil war of 1341–1347, Ivan Alexander participated energetically but pursued limited territorial objectives. An agreement with the Constantinopolitan regency brought Bulgaria lands around Plovdiv, Perushtitsa, Tsepina, Stenimaka and toward Kosnik in 1344. Yet while Bulgaria concentrated on eastern Thrace, Dušan occupied most of Macedonia, Albania and parts of Epiros and Thessaly. Ivan Alexander did not combine his efforts with the independent Rhodope ruler Momchil, whose principality disappeared in 1345, and he declined John Kantakouzenos’s proposal for joint action against the Turks under Serbian influence. The Tarnovo patriarch Simeon participated in Dušan’s imperial coronation at Skopje in April 1346, publicly acknowledging the emergence of a Serbian empire modeled partly on Bulgarian and Byzantine traditions. The peace with Serbia protected Bulgaria’s western border, but its strategic price was the abandonment of effective competition for Macedonia.

Ivan Alexander attempted to escape this increasingly narrow Balkan framework through maritime diplomacy. Venice had traded in Bulgarian lands since the late thirteenth century and established colonies at Varna, Mesembria, Anchialos and Sozopolis, purchasing grain, hides, wax and honey. A treaty in 1346 or 1347 formally regulated relations, and the tsar confirmed the connection in a letter to Doge Andrea Dandolo dated 4 October 1352. Bulgaria also opened less formal relations with Genoa: in May 1352 two envoys of the Genoese admiral Paganino Doria set out for Bulgaria while his fleet fought Venice in the Bosporus. Contact with both republics stimulated trade and broadened Bulgaria’s international connections, but it also drew the Black Sea coast into the rivalry of foreign maritime powers. In the later Dobruja polity, Ivanko’s treaty of 1387 granted extensive privileges to Genoa and may also have been directed against Tarnovo’s Venetian connection.

Dynastic policy within Ivan Alexander’s own household, however, accelerated political division. After marrying Theodora, a converted Jewish woman, he displaced Ivan Stratsimir, the son of his first marriage, in favor of Ivan Shishman. Shortly before 1360 Stratsimir received Vidin, which developed into a separate principality and then a царство with its own coinage and diplomacy. In northeastern Bulgaria the territories of Balik and his successor Dobrotitsa likewise moved from appanage toward independence. Thus three Bulgarian political centers emerged: Tarnovo, Vidin and Dobruja. Their rulers could negotiate separately with Hungary, Byzantium, Wallachia, Genoa and the patriarchate of Constantinople, but this diplomatic pluralism represented the disintegration of central authority rather than a coordinated federal strategy.

The Hungarian conquest of Vidin in 1365 demonstrated both the dangers of division and the continuing value of coalition diplomacy. King Louis I captured the city on 2 June, imprisoned Ivan Stratsimir and his family, established a Hungarian administration and promoted Catholic conversion. In 1366 Ivan Alexander refused passage through Bulgaria to Emperor John V Palaiologos on his return from seeking western assistance against the Turks. John’s cousin, Count Amadeus VI of Savoy, retaliated along the Bulgarian Black Sea coast, taking Agathopolis, Skafida, Sozopolis, Anchialos, Mesembria and Emona and besieging Varna. Negotiations, in which Dobrotitsa played an important role, secured John V’s passage and ended the siege. Dobrotitsa received Varna, Emona and Kozyak, while the abandoned coastal towns passed to John V, who undertook to help liberate Vidin. He supplied 180,000 florins to the Wallachian voivode Vladislav Vlaicu for operations against Hungary. Vidin was restored in 1369, but Ivan Stratsimir returned as Louis’s vassal; Hungarian guarantees, including the retention of his daughters at court, strengthened his independence from Tarnovo.

By then the Ottoman advance had displaced Byzantium as the central problem of Bulgarian diplomacy. Turks first employed as allies in Byzantine civil wars became enemies of all the Balkan states; they established a permanent base at Gallipoli in 1354, took Didymoteichon around 1359–1361 and held Adrianople by about 1368–1369. Bulgaria, Byzantium and Serbia nevertheless remained divided. After Ivan Alexander’s death on 17 February 1371 and the defeat of Balkan forces at Chernomen on 26 September, Ivan Shishman became a vassal of Sultan Murad I. Tarnovo Bulgaria formed a temporary shield between the Ottomans and Vidin, while dynastic concessions, including the fate of Ivan Shishman’s sister Kera Tamara, helped preserve an insecure peace. Traditional Bulgarian-Byzantine rivalry now lost much of its practical meaning: the Ottoman ruler, rather than the Byzantine emperor, increasingly determined the conditions under which Bulgarian rulers could survive.

The final diplomatic landscape was consequently one of separate Bulgarian courts pursuing separate accommodations. Ivan Stratsimir asserted full tsarist status and transferred the Vidin church from Tarnovo to the jurisdiction of Constantinople. Dobrotitsa acted as an autonomous Black Sea ruler, allied with Ivan Alexander against Hungary but later pursued his own relations with Byzantium; in November 1373 his unnamed daughter married Michael Palaiologos, son of John V. His successor Ivanko turned to Genoa, while Wallachia and Byzantine appanage holders subsequently competed for Dobruja under the shadow of Ottoman suzerainty. Tarnovo fell on 17 July 1393, Ivan Shishman was executed on 29 October 1395, and the defeat of King Sigismund’s crusading army at Nicopolis on 25 September 1396 was followed by the conquest of Vidin and the captivity of Ivan Stratsimir. The diplomatic history of the Second Bulgarian Empire had thus moved from the pursuit of universal recognition and Balkan hegemony to a struggle for local survival. Its rulers had repeatedly used crowns, marriages, embassies, church jurisdiction, commercial privileges and shifting alliances with sophistication, but no diplomatic instrument could compensate indefinitely for territorial fragmentation and the rise of an imperial power able to dominate every remaining Bulgarian center separately.