The Croatian–Bulgarian Wars were a series of conflicts that erupted three times during the 9th and 10th centuries between the medieval realms of
Croatia
Croatia, officially the Republic of Croatia, is a country in Central Europe, Central and Southeast Europe, on the coast of the Adriatic Sea. It borders Slovenia to the northwest, Hungary to the northeast, Serbia to the east, Bosnia and Herze ...
and
Bulgaria
Bulgaria, officially the Republic of Bulgaria, is a country in Southeast Europe. It is situated on the eastern portion of the Balkans directly south of the Danube river and west of the Black Sea. Bulgaria is bordered by Greece and Turkey t ...
. During these wars, Croatia formed alliances with
East Francia and
Byzantium
Byzantium () or Byzantion () was an ancient Greek city in classical antiquity that became known as Constantinople in late antiquity and Istanbul today. The Greek name ''Byzantion'' and its Latinization ''Byzantium'' continued to be used as a n ...
against the
Bulgarian Empire.
First war

During the middle of the 9th century,
Bulgaria
Bulgaria, officially the Republic of Bulgaria, is a country in Southeast Europe. It is situated on the eastern portion of the Balkans directly south of the Danube river and west of the Black Sea. Bulgaria is bordered by Greece and Turkey t ...
was the dominant power in the central, eastern, and northern Balkans. In 854, the Bulgarian ruler
Boris I forged an official alliance with the
Moravian prince
Rastislav against
Louis the German
Louis the German (German language, German: ''Ludwig der Deutsche''; c. 806/810 – 28 August 876), also known as Louis II of Germany (German language, German: ''Ludwig II. von Deutschland''), was the first king of East Francia, and ruled from 8 ...
of
East Francia. Duke
Trpimir of
Croatia
Croatia, officially the Republic of Croatia, is a country in Central Europe, Central and Southeast Europe, on the coast of the Adriatic Sea. It borders Slovenia to the northwest, Hungary to the northeast, Serbia to the east, Bosnia and Herze ...
was a faithful
Frankish vassal
A vassal or liege subject is a person regarded as having a mutual obligation to a lord or monarch, in the context of the feudal system in medieval Europe. While the subordinate party is called a vassal, the dominant party is called a suzerain ...
and was wary of Bulgaria's ongoing expansion when it reached Croatian borders after the wars against
Serbia
, image_flag = Flag of Serbia.svg
, national_motto =
, image_coat = Coat of arms of Serbia.svg
, national_anthem = ()
, image_map =
, map_caption = Location of Serbia (gree ...
. Bulgaria is said to have invaded Croatia in approximately 854, but there is also a possibility that King Louis gave some compensation to Trpimir to attack
Bulgaria
Bulgaria, officially the Republic of Bulgaria, is a country in Southeast Europe. It is situated on the eastern portion of the Balkans directly south of the Danube river and west of the Black Sea. Bulgaria is bordered by Greece and Turkey t ...
. During the war of 854, there was only one great battle on the territory of present-day northeastern
Bosnia, and neither side emerged victorious. Soon afterward, peace negotiations began between Boris of Bulgaria and Trpimir of Croatia, resulting in gifts exchanged and the establishment of peace, with the border between the
Croatian Duchy and Bulgaria stabilized at the river of
Drina (between modern-day
Bosnia and Herzegovina
Bosnia and Herzegovina, sometimes known as Bosnia-Herzegovina and informally as Bosnia, is a country in Southeast Europe. Situated on the Balkans, Balkan Peninsula, it borders Serbia to the east, Montenegro to the southeast, and Croatia to th ...
and
Republic of Serbia).
Second war
A very long and arduous war was prosecuted between the Bulgarian
Tsar
Tsar (; also spelled ''czar'', ''tzar'', or ''csar''; ; ; sr-Cyrl-Latn, цар, car) is a title historically used by Slavic monarchs. The term is derived from the Latin word '' caesar'', which was intended to mean ''emperor'' in the Euro ...
Simeon I, who wanted to take over the Byzantine Empire, and the Empire's monarch
Romanos I. Under heavy pressure from the Bulgarians and amassing defeat after defeat, the Byzantine Empire negotiated with Serbia and Croatia in an effort to forge an alliance against the Bulgarians. Having been informed of these plans by Prince
Michael of Zachlumia, who was forced to the islands as the Serbian rulers took direct control of most of his local lands for themselves, Simeon overran Serbia in 924, destroyed it by tricking its nobility, and made it directly part of the Bulgarian Empire. Serbia's ruler Zaharija Pribislavljević fled and found exile at the Croatian court, while after the realm's destruction massive waves of
Serb refugees fled and found refuge in
Tomislav's Croatia. Trying to gain Croatian entry into this coalition, Romanos I ordered the province of
Dalmatia
Dalmatia (; ; ) is a historical region located in modern-day Croatia and Montenegro, on the eastern shore of the Adriatic Sea. Through time it formed part of several historical states, most notably the Roman Empire, the Kingdom of Croatia (925 ...
in ca. 925 to pay taxes not to Byzantium but rather to the Croatian state; the Dalmatian territories, including most cities and the northern islands, were henceforth administered by King Tomislav and were to remain under Croatia. Tsar Simeon sent Duke
Alogobotur to drive the Serb refugees further into Croatia, causing outright war in ca. 926.
The climax of the war was the
Battle of the Bosnian Highlands that same year,
[Bakalov, ''Istorija na BÇŽlgarija'', "Simeon I Veliki".] when Croatian forces under the command of King Tomislav completely defeated the Bulgarian forces under the command of Alogobotur, killing most of the Bulgarians in the battle. The Croatian victory was so decisive and the battle so big that contemporary sources greatly overestimated Croatia's Army at 160,000 men, with a slightly bigger force on the Bulgarian side. This was the only battle Tsar Simeon ever lost. Since both rulers maintained good relations with
Pope John X, the pope was able to negotiate an end to the war soon afterward without any further border changes. Although the eastern border was extended down to the
river of Bosnia, the Croatian realm was greatly strengthened both militarily and in natural resources: it emerged from the war as one of the most modern realms of the period and was able to consolidate a moderately sized navy. On the same day as the battle Simeon died in
Preslav and his successor
Peter I faced internal difficulties and revolts by his brothers
Michail and Ivan. The Serbs were able to take advantage of this situation and many of them returned by 931 to their homes in the
renewed Serbian realm, thus terminating Croatia's short-lived Bulgarian neighbor at the east.
Third war
In the second half of the 10th century, the Croatian realm was ruled by
Stjepan Držislav. Stjepan formed an alliance with the
Byzantine Empire
The Byzantine Empire, also known as the Eastern Roman Empire, was the continuation of the Roman Empire centred on Constantinople during late antiquity and the Middle Ages. Having survived History of the Roman Empire, the events that caused the ...
, which in turn recognized him as the King of his lands. After his death in 997, his son
Svetoslav Suronja continued his pro-Byzantine policy. His brothers
Krešimir III and
Gojslav did not want Svetoslav as ruler and attempted a
coup d'etat, asking the Bulgarian tsar
Samuil for help. Answering their call, Samuil went on a rampage in 998 and razed the Dalmatian cities of
Trogir and
Split, but he was stopped at the
siege of Zadar. The Bulgarian forces then returned home,
[ Chronicle of the Priest of Duklja] using the Bosnian route. Territory taken by Samuil during the war was given to Krešimir III and Gojslav, who, with further Bulgarian support, won the Croatian
civil war
A civil war is a war between organized groups within the same Sovereign state, state (or country). The aim of one side may be to take control of the country or a region, to achieve independence for a region, or to change government policies.J ...
and took over the realm in the year 1000. Svetoslav Suronja, a Byzantine and Venetian ally, was sent to exile in
Venice
Venice ( ; ; , formerly ) is a city in northeastern Italy and the capital of the Veneto Regions of Italy, region. It is built on a group of 118 islands that are separated by expanses of open water and by canals; portions of the city are li ...
, but after a change in government there he was exiled to
Hungary
Hungary is a landlocked country in Central Europe. Spanning much of the Pannonian Basin, Carpathian Basin, it is bordered by Slovakia to the north, Ukraine to the northeast, Romania to the east and southeast, Serbia to the south, Croatia and ...
. Following the death of
Ivan Vladislav in 1018, Bulgaria fell under Byzantine rule, and Krešimir III and Gojslav, the two Croatian kings, became Byzantine vassals.
Footnotes
{{DEFAULTSORT:Croatian-Bulgarian Wars
Wars involving the First Bulgarian Empire
Wars involving medieval Croatia
850s conflicts
920s conflicts
990s conflicts
9th century in Bulgaria
10th century in Bulgaria
wars
War is an armed conflict between the armed forces of State (polity), states, or between governmental forces and armed groups that are organized under a certain command structure and have the capacity to sustain military operations, or betwe ...
Bulgarian wars