Kaloyan the Romanslayer (Калоян Ромеоубиец), Ivan I (Иван I, also Йоан I, Ioan I, in English John I), ruled as emperor (tsar) of Bulgaria 1197-1207. He was born in about 1168/1169. The name Kalojan (in Latin Caloiohannes), signifies the "Good John" or the "Handsome John", and is derived from Greek Kaloiōannēs, a standard augmentation of the names of Byzantine emperors named "John" (Iōannēs) in the Komnenian and later periods. (Byzantine enemies secretly called him Skyloïōannēs, or the "Dog Ioan".) Another of his nicknames was Ioannitsa (Йоаница, Ioannica), variously rendered Ioannitza, Ivanitsa (Иваница, Ivanica), a diminutive form of Ivan or Ioan (John in Еnglish).
Kaloyan pursued his predecessors' aggressive policy against the Byzantine Empire to the point of making an alliance with Ivanko, the murderer of Ivan Asen I, who had entered Byzantine service in 1196 and had become governor of Philippopolis (Plovdiv). Another ally of Kaloyan was Dobromir Hriz (Chrysos), who governed the area of Strumica. The coalition was quickly dissolved, as the Byzantines overcame both Ivanko and Dobromir Hriz. Nevertheless, Kaloyan conquered Konstanteia (Simeonovgrad) in Thrace and Varna from the Byzantine Empire in 1201, and most of Slavic Macedonia in 1202.
In 1202 King Imre of Hungary invaded Bulgaria and conquered the areas of Belgrade, Braničevo (Kostolac), and Niš (which he turned over to his protege on the throne of Serbia, Vukan Nemanjić). Kaloyan retaliated in 1203, restoring Vukan's brother Stefan Prvovenčani (Stefan the First-Crowned) in Serbia and recovering his lands after defeating the Hungarians. Ill feeling between Bulgaria and the Hungarians continued until the intercession of Pope Innocent III.
Innocent III had written to Kaloyan, inviting him to unite his Church with the Roman Catholic Church, as early as 1199. Wanting to bear the title of Emperor and to restore the prestige, wealth and size of the First Bulgarian Kingdom, Kaloyan responded in 1202. In this political maneuver, he requesed that Pope Innocent III bestow on him the imperial crown and sceptre that had been held by Simeon I, Peter I, and Samuel and in exchange he might consider communication with Rome. Kaloyan also wanted the Papacy to recognize the head of the Bulgarian Church as a Patriarch. The pope was not willing to make concessions on that scale, and when his envoy, Cardinal Leo, arrived in Bulgaria, he anointed the Archbishop Vasilij of Tărnovo as Primate of Bulgarians and Vlachs. Kaloyan only received Uniate crown as rex Bulgarorum et Blachorum ("King of Bulgarians and Wallachians") or rex Bulgarie et Blachie ("King of Bulgaria and Wallachia"), not emperor. Blithely Kaloyan wrote to the pope, thanking him for an imperial coronation and for the anointing of his patriarch. He also assured him that he too will follow the Catholic Church rites, as part of the agreement. Meanwhile, in an attempt to foster an alliance with Kaloyan, the Byzantine Emperor Alexios III Angelos recognized his imperial title and promised him patriarchal recognition.
Immediately afterwards, in 1204, the Fourth Crusade captured Constantinople and created the Latin Empire, electing as emperor Baldwin I of Flanders. Although Kaloyan had offered the crusaders an alliance against the Byzantine Empire, his offer had been declined, and the Latin Empire expressed the intention of conquering all the lands of the former Byzantine Empire and its neighbours. The impending conflict was precipitated by the Byzantine aristocracy in Thrace, which rebelled against Latin rule in 1205 and called on Kaloyan for help, offering him its submission.
As the Latin Emperor Baldwin I began to subdue rebel cities and besieged Adrianople, in the words of the Crusader chronicler Villehardouin, "Johannizza, King of Wallachia, was coming to succour Adrianople with a very great host; for he brought with him Wallachians and Bulgarians, and full fourteen thousand Comans who had never been baptised" (Villehardouin, 92). On April 14, 1205, Kaloyan's Cumans managed to draw the pursuing heavy cavalry of the Latin Empire into an ambush in the marshes north of Adrianople, and Kaloyan inflicted a crushing defeat on the Crusader army. Emperor Baldwin I was captured, Count Louis I of Blois was killed, and the Venetian Doge Enrico Dandolo led the surviving portions of the Crusader army into a hasty retreat back to Constantinople, during the course of which he died of exhaustion. (Baldwin was imprisoned in the Bulgarian capital Tărnovo until he died or was executed later in 1205.) During the course of 1205, Kaloyan defeated the Latins at Serres and captured Philippopolis (Plovdiv), overrunning much of the territory of the Latin Empire in Thrace and Macedonia.
In spite of the initially welcome successes of Kaloyan against the Latins, the Byzantine aristocracy eventually began to conspire against his rule. Kaloyan also changed course, and turned mercilessly on his former allies, adopting the sobriquet Rōmaioktonos ("Romanslayer"), as a counter-derivative from Basil II's Boulgaroktonos ("Bulgarslayer").
On January 31, 1206 Kaloyan defeated the Latins again in the battle of Rusion, and later proceeded to capture Dimotika. The Bulgarians repeatedly ravaged Thrace, including the important cities of Herakleia and Caenophrurion (Çorlu), and prompting the evacuation of other cities, such as Rodosto (Tekirdağ). Whereas in the past Kaloyan had limited his ferocity to outsmarting his enemies, his later campaigns included wholesale transfer of populations from the captured cities to distant regions in Bulgaria.
The sources on Kaloyan's reign are for the most part foreign (Byzantine and Latin) and hostile, stressing his brutality and cruelty. Some of this ruthlessness has been ascribed specifically to his Cuman envoy, while others have pointed out that Kaloyan's most repressive policies were aimed at the destruction of the enemy elite, while commoners were often treated with mercy. One of the stories about the demise of the Latin Emperor Baldwin describes his cruel dismemberment by an enraged Kaloyan, whose wife had falsely alleged that Baldwin had propositioned her, when he had in fact spurned her advances. The story is reminiscent of Joseph and Potiphar's wife, but fit well with the hostility of contemporary sources, which also suggest occasional outbursts of rage. Kaloyan's corpse (together with his personal signet ring) was discovered buried in the Church of the Holy Forty Martyrs in Tărnovo. Forensic examination of the skull has revealed damage to the head incurred in youth, which may have pressed against the brain and occasionally caused considerable pain and outbursts of rage.
Ultimately Kaloyan's reign was a period of growth and political ascension of the Bulgarian kingdom, which expanded the political and economic gains of his brothers Assen and Peter. He is considered to be one of the great Bulgarian kings.
He had a daughter, Maria of Bulgaria, by an early marriage. She married the Latin Emperor of Constantinople Henry of Flanders to strengthen the new alliance between Tsar Boril of Bulgaria and Henry. Maria is suspected to have taken part in the assassination of Henry, who died of poison on June 11, 1216.
Contemporary papal and native sources name Kaloyan ruler of (omnium) Bulgarorum atque Blachorum ("(all) Bulgarians and Wallachians"), of (totius) Bulgarie ac Blachie ("(all) Bulgaria and Wallachia"), or simply of Bulgaria/Bulgarians in the diplomatic exchange. Similarly, the head of the church (Archbishop Vasilij of Tărnovo) is described as presiding over Bulgarorum et Blacorum Ecclesiam ("the Bulgarian and Wallachian Church").
The contemporary Byzantine historian Niketas Choniates alternates interchangeably between the terms Mysoi, Boulgaroi, and Blachoi for the people, preferring Mysia for the country, and Blachos for describing persons and language. It is inferred that geographically the medieval Wallachia in question (distinct from both Great Wallachia in Thessaly and the later Wallachia north of the Danube), overlaps with the former Roman province of Moesia Inferior (Greek Mysia, Choniates, 481), as distinct from the Byzantine theme of Bulgaria further west (Choniates, 488). This distinction is corroborated by a slightly earlier contemporary, the chronicler of the Third Crusade, who describes Kaloyan's predecessors as rulers "of the Wallachians and the greater part of the Bulgarians" (Blacorum et maxime partis Bulgarorum) in 1189 (Ansbert, 58).
The Byzantine historian from XIII century Theodor Scutariota named Kaloyan "the Bulgarian Ioan" or "Bulgarian basileus" and wrote about "Bulgarians", "Bulgarian land", "Bulgarian matters"; also he defined Ivan Asen I as "tsar of the Bulgarians. The same "probulgarian" point of view about the same persons and events was shared by several other Byzantine authors from XIII and XIV centuries like George Acropolites, George Pachymeres and Nicephorus Gregoras.
The native sources, written in Old Bulgarian language and used domestically, including the lead seals of the Bulgarian rulers from Ivan Asen I to Boril use the term "Emperor of the Bulgarians", as do the literary sources (for example the Synodik of Boril) together with the terms "Bulgarian land", and "Bulgarian tongue".
Roughly from the reign of Tsar Boril and already in the time of Tsar Ivan Asen II the names Wallachia, Wallachians and Wallachian totally disappeared from all historical sources, connected with the Second Bulgarian Empire. The subsequent native sources, all written in Old Bulgarian language, without exceptions treat the state as Bulgarian in the line of tsar's title of Ivan Asen II from his Turnovo's inscription from 1230 "In Christ the Lord good and faithful Tsar and autocrat of the Bulgarians, son of the old Asen", an inscription from Boyana Church from 1259 "This was written in the Bulgarian Empire under the pious and devout Tsar Constantine Asen" and one marginal note from 1269/70 "In the days of the faithful tsar Constantine, who ruled the Bulgarian throne" . (Still more, the names Wallachia, Wallachians and Wallachian weren't mentioned by the earlier Byzantine authors like Michael Psellos, Anna Komnene and Michael Attaliata in similar context about the lands and population between the Danube and the Rhodope mountains. This historiographical situation narrows the usage of the "Vlach's terminology" in corresponding meanings for period of only two decades - between 1186 and 1207.)
The evidence of much later works involves various levels of contradictory inference. For example, the Venetian chronicle of Paolo Ramusio, finished in 1573 and printed in Italian and Latin from 1604 to 1634, states that Mysia (Moesia Inferior) was composed of the provinces of Wallachia and Bulgaria . The contemporary work of Mauro Orbini, Il Regno degli Slavi, published in Pesaro in 1601, cites similar sources but virtually ignores "Wallachians" and uses "Bulgarians" throughout, but his interpretation is a matter of controversy . The "Vlach interpretation" was totally ignored also by the Franciscan monk Blasius Kleiner in his History of Bulgaria, written in 1761, and the Serbian historian Jovan Rajić in his History of Various Slav peoples and Especially of Bulgarians, Croats and Serbs, published in 1795. The same treatment was accepted also by the Bulgarian enlightener Paisiy Hilendarski in his Istoriya Slavyanobolgarskaya, written in 1762.
The modern implications of these names are ethnic and cultural rather than geographical, and they are fiercely disputed. Much can be conjectured from them concerning the Romance-speaking and Slavic-speaking populations over which Kaloyan ruled, the precise extent of his empire, and his own ethnic connections. These formulae and descriptions emphasise that his power drew on more than one source. He desired to link himself to the former Bulgarian Empire, stressing the Papal origins of his crown by claiming (perhaps with some accuracy), that the Papacy had granted an imperial crown to the rulers of the First Bulgarian Empire, as noted above. In his correspondence with him, Pope Innocent III suggested that Kaloyan was descended both from the emperors of the First Bulgarian Empire, and from the nobility of the city of Rome.
The academic tradition of interpretation of the wide use of the name "Vlachs" in this particular case as nothing more than a transient substitution and confusion of several medieval authors was affirmed in the second half of the 19th century by the Czech historian Konstantin Josef Jireček in his "History of the Bulgarians", first published in 1876, in which he ignored the idea of significant ethnic Vlach participation in these processes, and is supported by the contemporary Bulgarian medievalist and researcher of the Asens Ivan Bozhilov.