About
Tomislav, Latin: Tamisclaus, was the first king of Croatia. He became Duke of Croatia around 910 and was crowned king in 925, reigning until 928. During Tomislav’s rule, Croatia forged an alliance with the Byzantine Empire against Bulgaria. Croatia’s struggles with the First Bulgarian Empire eventually led to war, which culminated in the decisive Battle of the Bosnian Highlands in 926. In the north, Croatia often clashed with the Principality of Hungary; the state retained its borders and, to some extent, expanded with the disintegrated Lower Pannonia.
Tomislav attended the 925 Council of Split, convened by Pope John X, to discuss the use of Slavic languages in liturgy and ecclesiastical jurisdiction over both Croatia and the Byzantine Theme of Dalmatia. Although the Pope sought to prohibit Slavic liturgy, the council did not agree. Jurisdiction over the region was given to the Archbishop of Split instead of Bishop Gregory of Nin. Since historical information on Tomislav is scarce, the exact years of his accession and death are unknown. The reigns of his successors were marked by a series of civil wars in Croatia and a gradual weakening of the country.
Reign
Duke of Croatia Although Tomislav’s ancestry is unknown, he might have been a member of the Trpimirović dynasty. There is a nearly twenty-year difference between the first documentation of Tomislav and the last mention of Muncimir, his predecessor as Duke of Croatia. Historical records of Tomislav are scarce, but it is assumed that he was a son of Muncimir. Tomislav succeeded Muncimir, son of Trpimir I, as duke around 910 or after others ruled following Muncimir’s death. In any case, Tomislav came to the Croatian throne sometime between 910 and 914. In the History of Salona, a 13th-century chronicle by Thomas the Archdeacon of Split, Tomislav was mentioned as Duke of Croatia in 914.
After the Hungarian conquest of the Carpathian Basin in the late 9th and early 10th centuries, the Hungarians immediately began raiding and expanding their territory. They threatened Lower Pannonia, still nominally under Frankish suzerainty, and killed Braslav, the last Pannonian duke. The Hungarians also fought Croatia, although it was not a primary target of their raids.
The Chronicle of the Priest of Duklja mentions that Tomislav, who ruled for 13 years, successfully fought the Battle of Drava River with the Hungarians. Since the Venetian chronicler Andrea Dandolo and a notary of King Béla III mention Hungarian victories against Croatia in the same period, however, both sides had gains. Croatia maintained its northern borders and expanded into part of the collapsed Pannonian Duchy, including its former capital Sisak. The plains north of Sisak were difficult to defend against Hungarian cavalry, but Sisak had been well-fortified since the reign of Duke Ljudevit. The sparsely-populated area between the Sava and Drava rivers was on the outskirts of Hungary and the Duchy of Croatia, so neither country could strengthen its rule there after the Duchy of Pannonia dissolved.
East of Croatia, the First Bulgarian Empire’s power increased significantly. After a war between the Bulgarian knyaz Boris I and Croatian Duke Trpimir I, Croatian-Bulgarian relations were fairly good. Papal legates regularly crossed Croatian territory, where they received protection, to Bulgaria. The situation changed in the 10th century during the reign of Simeon I, who decided to subordinate the Byzantine Empire to himself.
Tomislav’s realm covered most of southern and central Croatia and the Dalmatian coast, excluding the Theme of Dalmatia, parts of present-day western Herzegovina, and northern and western Bosnia. During the early 10th century, Croatia was divided into 11 counties: Livno, Cetina, Imotski, Pliva, Pset, Primorje, Bribir, Nona, Knin, Sidraga, and Nin. Three counties, Lika, Krbava, and Gacka, were ruled by a ban. After its expansion, Tomislav’s state presumably contained more than eleven counties. Byzantine emperor and chronicler Constantine VII writes in De Administrando Imperio that at its peak, Croatia could have raised a military force composed of 100,000 infantry, 60,000 horsemen, and a naval fleet of 80 large ships and 100 smaller vessels. However, these figures are viewed as a considerable exaggeration of the size of the Croatian army. According to palaeographic analysis of the manuscript of De Administrando Imperio, the population of medieval Croatia was estimated at 440,000 to 880,000; its military force probably consisted of 20,000–100,000 infantrymen and 3,000–24,000 horsemen organized into 60 allagia.