The Romans in the second century BCE had subjugated various parts of Illyria, such as Histria in 177 BCE and the Ardaeian kingdom in 168 BCE, when they defeated the army of king Gentius.

Southern Illyriafrom 167 BCE had become a formally independent protectorate of the Romans, for whom the region has considerable strategic and economic importance.

It possesses a number of important commercial ports along its coastline, and has gold mines in its interior regions.

Illyria is also the starting point of the Via Egnatia, the great Roman road that runs from Dyrrachium (modern Durazzo), on the Adriatic, to Byzantium in the east.

Next came the interior of the western Balkans, accumulating in the wars with the Dalmatae in 156BCE  and 78 BCE, and in 129 BCE against the Iapydes.

Illyricum in 59 BCE after the Lex Vatinia had been assigned as provincia together with Cisalpine Gaul (zone of responsibility rather than the province as is understood today) to Caesar.

No province had been established until Octavius's wars in Illyricum during 35-33 BCE.

Caesar's assassination had encouraged the Illyrians to regain their liberty.

They refused to pay taxes and destroyed five cohorts of the army commanded by P. Vatinius, also killing the senator Bebius.

The Roman senate had charged Marcus Junius Brutus, one of the assassins of Caesar, to lead the army in Illyria and Macedonia.

He had marched in the winter of 42 BCE from Greece at the head of the army, through roads covered by snow, doubtless coming along the Via Egnatia in order to appear by surprise before the walls of Dyrrhachian, sick with exhaustion and the cold.

Brutus after this took Apollonia and Byllis, pursuing and breaking the power of Gaius Antonius, who withdrew to Buthrotum.

Octavius in 35 BCE had been compelled to revisit Illyrian lands yet again, this time Dalmatia.

At the head of ten legions, he had marched from the north and subjugated the Iyapedes, Liburnians and Pannonians.

The most difficult war proved to be with the Dalmatians, in which the young future emperor was wounded twice, as Suetonius writes, first in the knee with a stone from a slingshot and later when a bridge fell during the siege of the Iapydian city of Metulum.

Octavian in that siege had seen with his own eyes the bravery of the Illyrians.

After managing to conquer the upper part of the city, Octavian had asked the inhabitants to surrender their weapons, but they collected their women and children and locked them in the council building, putting guards around it and ordering them to set the building on fire if the men were to suffer any harm.

After taking these measures they assailed the Romans in desperation, but since they were down below and the Romans above, they were badly broken and all were killed.

The assembly guards then set the building on fire, as they had been ordered, and many women and children were burned to death; and even more threw themselves on the fire, along with their children.

Together with them the city was burned so completely, that although it had been a very large city, not a trace of it remains.

The first mention of the province of Illyricum had occurred in the context of the Augustan settlement of 27 BCE.

The province was subsequently enlarged as the Romans expanded their power in the region through a series of wars known as Pannonian wars (Bellum Pannonicum), fought from 12 BCE -9 BCE against group of peoples known as the Pannonians.

The taxes imposed by the Romans are greatly resented by the native Illyrians, who are frustrated by this new shift of power.

The Romans often treat the their subjects terribly, selling the women and children as slaves and destroying their settlements.

The turn of the millennium has also seen the recruitment of many Illyrian soldiers into the Roman army to fight against the Germanic tribes in the north.

The widening gap between the Roman government and its subjects in Illyricum leads ultimately to the great revolt that begins in the spring of CE 6, when several regiments of Daesitiates, natives of the area that now comprises central Bosnia and Herzegovina, are gathered in one place to prepare to join Augustus's stepson and senior military commander Tiberius in a war against the Germans.

Instead, the Daesitiates, led by Bato the Daesitiate (Bato I), mutiny and defeat a Roman force sent against them.

Bato II is captured soon afterwards by Bato of the Daesitiates, whose assembly puts the Bato of the Breuci to death.

Tiberius and Germanicus launch an operation against the Daesitiatesin the next year.

Bato and the Daesitiates after fierce battles surrender to Tiberius in  September CE 9, only a few days before the Battle of Teutoburg Forest.

This is just in time: the Roman high command does not doubt that Arminius and the Cherusci would have formed a grand alliance with the Illyrians.

It has taken the Romans three years of hard fighting to quell the revolt, which is described by the Roman historian Suetonius as the most difficult conflict faced by Rome since the Punic Wars two centuries earlier.

It is alleged that when Tiberius asked Bato and the Daesitiates why they had rebelled, Baton was reputed to have answered: "You Romans are to blame for this; for you send as guardians of your flocks, not dogs or shepherds, but wolves."

Bato will spend the rest of his life in the Italian town of Ravenna.

Croats and Serbs settle during the seventh century in the lands that make up modern Bosnia and Herzegovina.

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.