East Central Europe (820 – 963 CE): Carolingian Frontiers, Great Moravia, and the Magyar Ingress

Simeon's troops under Alogobotur invade Croatia in 926, at this time an ally of Constantinople.

The reason might have been that Tomislav had received and protected the Serbs who were expelled by Simeon from Rascia.

In all probability, however, the main reason is that Simeon, if crowned by the Papal Legate, fears an attack from the Emperor Romanos Lekapenos, supported by Tomislav.

Romanos had won the friendship of Tomislav some years previously, handing over Dalmatia to Tomislav and recognizing him as King of Croatia (Pope John X had recognized Tomislav as King of Croatia in 925).

Tomislav had sent his troops to Italy during the summer of 926 to expel Saracens from the city of Sipontus, which belongs to the imperial province of Langobardia.

This event could have been sufficient proof to Simeon that the Croats had taken the side of Constantinople and that they would support the Greek emperor actively in the future.

Therefore, when Simeon sends a great army against the Croats, the Bulgarians are met by Tomislav's army in the mountainous region of Eastern Bosnia.

The Croatian forces under the leadership of their king completely devastate the Bulgarian army.

Key to Tomislav's triumph is likely the choice of terrain on which the battle takes place: Croatian soldiers are probably more skilled in fighting in the mountainous terrain of the Bosnian highlands.

The Croatian victory is so decisive and the battle so big that contemporary sources greatly overestimate Croatia's army at one hundred and sixty thousand men, with a slightly bigger force on the Bulgarian side.

This is the only battle Tsar Simeon ever loses.

Since both rulers maintain good relations with John X, the pope is able to negotiate an end to the war soon afterward without any further border changes.

Tomislav, fearing Bulgarian retribution, accepts to abandon his union with Constantinople and make peace on the basis of the status quo, negotiated by the papal legate Madalbert.

…northeast through Bosnia and …

Bosnia’s hereditary ban Stjepan II Kotromanic, having reigned from 1314, has expanded his nation as far north as the Sava River and …

Many in Bosnia switch loyalty to Murad after the last Nemanja ruler dies in 1371.

Tvrtcko I, the prominent ban of Bosnia who had earlier adopted the title of King of Bosnia and Serbia, has annexed eastern Herzegovina, part of Serbia/Raska (as far as the monastery at Mileseva), and Dalmatia nearly to Venice’s port of Zadar.

After the defeat of Nikola Altomanović, Prince Lazar had emerged as the most powerful lord on the territory of the former Serbian Empire.

He wants to reunite the Serbian state, and the Serbian Orthodox Church sees him as most fitted to succeed the Nemanjić dynasty.

The Church, which is the strongest cohesive force among the Serbs at the time, does not support Tvrtko's aspirations in this regard.

Tvrtko I had by 1390 expanded his realm to include a part of Croatia and Dalmatia, making Bosnia the major Slavic state in the Balkans.

At the peak of his power, he is "King of Bosnia, Serbia, Croatia, Hum, Usora, Soli, Dalmatia, Donji Kraji", but after his death on March 20, 1391, the power of the Bosnian state will slowly fade in power and influence.

The Ottoman Empire has already started its invasion of Europe and will pose a major threat to the Balkans throughout the first half of the fifteenth century.

The Bosnian kingdom begins to disintegrate in 1391; the southern part becomes the independent Duchy of Herzegovina.

Stephen Dabiša, an illegitimate son of Vladislav Kotromanić, born after his half-brother Tvrtko I, succeeds Tvrtko I in 1391.

At the time of his ascension to power, Bosnia is already decentralized by the semi-independent nobility.

Beljak and Radič Sanković rule independently in the Hum and Popovo.

The Sankovići give Konavle to the Republic of Ragusa, which then starts to stir Kotor and other Dalmatian cities to revolt against the Bosnian King's rule, asking them to reaccept the supreme rule of the Hungarian King Sigismund, but they refuse.

King Stephen Dabiša in 1391 dispatches vojvoda Vlatko Vuković and knez Pavle Radenović to Konavle, where they oust the Sankovići and distribute their lands among themselves.

Beljak dies and Radič is imprisoned; thiis marks the end of the Sanković family.

The Ottoman Empire has started to invade Bosnia again and in 1392 King Stephen Dabiša dispatches Hrvoje Vukčić, who decisively defeats the Ottomans.

Dabiša will spend the rest of his reign quarreling with the Hungarian King Sigismund and the King of Naples Ladislaus for control over Croatia and Dalmatia.

King Ladislaus manages to win the Vukčić family to his side.

Vuk Vukčić, Dabiša's Ban, takes Ostrovica and Vrana from Ivaniš Paližna.

Dabiša desires to put Zadar under his supreme rule, but Vuk works for Ladislaus.

Hrvoje Vukčić recognizes Dabiša's supreme rule, stating that he will serve him as long as he breathes, after which he will serve the Hungarian King Sigismund.

At the beginning of 1394, the nobility under Ivaniš Horvat, a subject of Ladislaus, refuses to serve King Dabiša.

Dabiša dispatches Prince Ivan Radivojević to take Omiš from Horvat as a punishment.

The Hungarian King Sigismund moves to destroy both Horvat and Dabiša.

The Hungarian Army besieges and burns to the ground Dobor in the lower stream of Bosna.

Dabiša arrives here, recognizes King Sigismund's suzerainty and gives up Dalmatia and Croatia in his name.

In turn, the Hungarian King nominates him Prince of the Szomod Principality.

King Stephen Dabiša dies of an illness on September 8, 1395 and King Sigismund takes control over most of Bosnia, but the Bosnian Rusag elects Dabiša’s wife and consort, Jelena Gruba, to ascend the throne as queen regnant.

Bosnia had grown in both size and power under Stephen Tvrtko I, finally becoming an independent kingdom in 1377.

Tvrtko by 1390 had expanded his empire to include a part of Croatia and Dalmatia, and assumed the title of Bosnian King of Rascia, Bosnia, Dalmatia, Croatia and the Littoral.

His full title listed subject peoples and geographical dependencies, following the Eastern Roman norm.

At the peak of his power, he was King of Serbia, Croatia, Bosnia, Hum, Usora, Soli, Dalmatia, Donji Kraji, etc.

Following his death in 1391, however, Bosnia had fallen into a period of decline that will not be arrested.

Because the Ottoman Empire has begun its conquest of Europe and poses a major threat to the Balkans, Bosnia accepts the rule of Hungary-Croatia at the beginning of the fifteenth century.

The populous Bosnian nobility, having brought to power Queen Jelena Gruba, the first female ruler of Bosnia, in 1395, had dethroned her in 1398 and replaced her with King Stjepan Ostoja, a client of the powerful Duke Hrvoje Vukčić.

Ostroja, siding with King Ladislaus of Naples in his struggle against the Hungarian King Sigismund, Bosnia's liege, in 1403 wars against the Republic of Ragusa, a Hungarian vassal.

Tvrtko's son Stephen Ostoja had succeeded to the throne at the death of Bosnian ruler Jelena Gruba in 1398, and has since struggled for possession of the crown against Tvrtko's illegitimate son.

The Bosnian nobles, led by Hrvoje Vukčić and finding Stjepan Ostoja wanting as king, replace him with his half-brother, who takes the throne as Stefan Tvrtko II; Stjepan flees to Hungary.