Tomislav of Croatia

Tomislav was the first king of Croatia. He became duke in c. 910, was elevated to kingship by 925 and reigned until 928. At the time of his rule, Croatia forged an alliance with the Byzantines during their struggle with the Bulgarian Empire, with whom Croatia eventually went to war, culminating in the decisive Battle of the Bosnian Highlands in 926. To the north there were often conflicts with the Principality of Hungary. Croatia kept its borders and to some extent expanded on the disintegrated Lower Pannonia.