
Byzantine Emperor Basil I receiving delegation of Serbs
In the middle of the 5th century, the Huns led by Attila created a powerful state, which collapsed after his death in 453, and the Gepids and the Eastern Goths established their states on the territory of the present-day Serbia. In the early decades of the 6th century, the raids on the territory of the Eastern Roman Empire were joined by the Slavs, sometimes as independent invaders and sometimes united with other barbaric tribes. In the middle of the same century, the Avars arrived in the Balkan Peninsula, expanding their power and influence over the surrounding Slavs over the next half century, with whose help they invaded and plundered the Byzantine territories, and in 582 occupied Sirmium itself.
By the end of the century, the Slavs strengthened so much that already in 584 history recorded their permanent settlement in the areas south of the Sava and Danube, and two years later their attack on Thessaloniki.

Serbian migratory route
The turning point in the settlement of the Slavs was the coming to power of Emperor Heraclius in 610. He estimated that the war with Persia on the eastern borders of the empire was a far greater problem and, upon taking the throne, withdrew all remaining forces from the Danube border and shifted them east, paving the way for the permanent and unimpeded settlement of the Slavs, who in the ensuing decades flooded the entire Balkan Peninsula.
After the unsuccessful Slavic siege of Thessaloniki in 611 and the siege of Constantinople in 626, the Serbs migrated to the Balkans and present-day Serbia. According to the Byzantine emperor Constantine Porphyrogenitus (913-959), with the permission of Heraclius, they settled in the areas between the rivers Cetina and Vrbas in the west, Bojana, Ibar and Morava in the east, the Danube and the Sava in the north and the Adriatic Sea in the south. He also noted that the Serbs came from the region of Boika or White Serbia (the territory of present-day Czech Republic). Heraclius first settled them in an area west of Thessaloniki, most likely to defend the city from other Slavs, however, they decided to return to the White Serbia. They crossed the Danube, but when they saw that the Avars had strengthened their power again, they requested another land to settle through the strategos of Singidunum, so Heraclius assigned them Dalmatia.
Half a century later, more precisely in 680 AD, the people of Turkish origin, Proto-Bulgars, who settled east of the Serbs, came to the Balkans among the Slovenes in the area of former Thrace. Over the next centuries, they mixed with the surrounding Slavic mass and lost their language and customs, but imposed their name, the Bulgarians. Their country encompassed eastern Serbia with the Moravian Valley, Belgrade and Srem. The barbaric invasion destroyed the old Roman cities and structures, so that the next few centuries were characterized by the complete absence of any information about the events in the interior of the Balkan Peninsula.
The prince (archont) who led the Serbs in the migration to the Balkans was succeeded by his son, so that the power remained in the same family for centuries, but the first prince whose name was recorded was Viseslav, who presumably ruled the region in the 8th century. His great-grandson Vlastimir, who ruled in the first half of the 9th century, is considered the founder of the Serbian state in the Middle Ages. During his reign, Serbia was attacked by the neighbouring Bulgarians, who, however, suffered a total defeat in the three-year war, losing much of the army.
After Vlastimir’s death, around 851, the Bulgarians attacked Serbia again, but his sons Mutimir (851-891), Strojimir and Gojnik defeated the Bulgarians again, after which peace was concluded between the Serbs and the Bulgarians.
A power struggle ensued among Vlastimir’s sons, in which the eldest, Mutimir, won. During his reign, the ruling family received Christianity, and Pope John VIII (872-882) requested him in 873, after the success of the Moravian-Pannonian mission, to submit to Methodius, as a Slavic bishop, based in Sirmium. After Mutimir’s death in 891, Serbia was once again gripped by power struggle, from which Mutimir’s cousin Petar Gojnikovic emerged victorious (892-917). As the best man of the Prince of Bulgaria and then the most powerful ruler in the Balkans, Simeon the Great (Prince 893-913, Emperor 913-927), he was able to rule Serbia in peace for almost two decades. His reign was ended by Simeon himself, who received reports from Mihailo of Zachumlia about Peter’s contacts with his Byzantine opponents, after which Peter was captured by deception and Simeon appointed Mutimir’s grandson Pavle Branovic the new Prince (917-923).
A few years later, the Byzantines tried to overthrow him, with the help of his cousin, Zaharija Pribislavljevic, but he was captured and sent to Bulgaria. The strengthening of Bulgaria under Simeon forced Pavle to cross over to the Byzantine side, after which the Bulgarian emperor sent Zaharija to oust him in 923. However, Zaharija himself quickly crossed over to Byzantine side, forcing Simeon to send his army against him. The Bulgarian army was defeated, but the Bulgarian emperor sent a new army to Serbia, with which he also sent Vlastimir’s great-grandson Caslav Klonimirovic (931-960), who was to be appointed the new Prince. Faced with the new Bulgarian army, Zaharija fled to Croatia, while the Bulgarians invited Serbian zupans to come and yield to the new Prince. However, instead of appointing a new Prince, Serbian zupans were captured and all of Serbia was looted and annexed to Bulgaria.
After Simeon’s death in 927, Caslav fled Bulgaria and, with Byzantine help, rebuilt Serbia, with the largest cities being Dostinika (the first capital of Serbia), Tzernabouskeï, Megyretous, Dresneïk, Lesnik and Salines, while the “small land” of Bosnia, then part of Serbia, had the cities of Katera and Desnik. In the mid-10th century, the northern borders of Serbia began to be threatened by the Hungarians, and Prince Caslav died fighting them. His death extinguished the first Serbian ruling dynasty, the Vlastimirovics, who ruled the Serbs from arriving in the Balkans until the mid-10th century.
Decades later, in 971, the Bulgarian Empire collapsed and became part of Byzantium. The brutal Byzantine administration in parts of the Balkans inhabited by the Slavs, led to the rebellion in Macedonia in 976. The uprising quickly spread, with Samuil, later Emperor of Bulgaria, at the helm. After penetrating Greece, to Corinth and the Peloponnese, in about 998, he launched a march to the western parts of the Balkans and by 989 conquered much of present-day Serbia and the surrounding Serbian principalities. At the beginning of the 11th century, Byzantium led by Emperor Basil II began to suppress the uprising and after a great victory in Battle of Kleidion in 1014, Emperor Samuil died and his Empire virtually collapsed due to dynastic power struggles. As early as in 1018, the widow of the last Emperor surrendered with her whole family to Basil II, but some of Samuil’s military leaders continued to resist. The last of these was Sermon who ruled Srem. He was deceived and killed by the Byzantine commander of Belgrade in 1019, which ended the last remnant of Samuil’s state.
After the collapse of the Samuil’s uprising the Byzantine administration in the areas inhabited by the Slavic population began the process of Hellenization and the introduction of the taxes in cash, instead of, as before, in kind. These changes, along with the increase in taxes due to the Byzantine crisis, led to the rise of two new Slavic rebellions. First, in the summer of 1040, an uprising broke out in Pomoravlje, headed by the alleged Samuil’s grandson, Peter Delyan, who was declared Emperor in Belgrade. Although the uprising quickly spread to the present-day Serbia, Macedonia and northern Greece, it was suppressed already in 1041. Thirty years later, in 1072, a new uprising under the leadership of Georgi Voyteh broke out, and the insurgents proclaimed Duklja’s Prince Constantine Bodin the Emperor in Prizren. Under his leadership Nis was conquered, but at the end of the year, his army was defeated at Paun in Kosovo, which suppressed the uprising.
At the beginning of the following decade, Bodin, as the King of Zeta, occupied Raska and appointed Vukan and Marko zupans (circa 1083-1112). He subsequently conquered Bosnia, too, where he appointed Prince Stefan. The fighting with Byzantium since 1091 was led only by zupan Vukan from Raska, who penetrated Kosovo from Zvecan, burning Lipljan and later reaching Vranje, Skopje and Polog. He was replaced in power by his cousin Uros I, who allied with the Hungarians in fighting the Byzantium. His daughter Helen became the wife of the future King of Hungary Bela II, and his son Belos became the royal palatine.
Throughout the 12th century, the Hungarians fought against Byzantium, first around Srem and Belgrade, and then around the Moravian valley, and the zupans of Raska participated in almost every one of these wars as Hungarian allies. They succeeded in briefly conquering Belgrade and later Nis, but were suppressed by the Byzantines, led by the powerful Emperor Manuel I, so that all conflicts ended without significant territorial expansion. At the same time, Raska was shaken by internal power struggle between Uros’ sons Uros II and Desa, in which Emperor Manuel himself took part. The Byzantine Emperor eventually appointed Tihomir, the son of a local lord Zavid, as the new grand zupan.

Serbian states in the 9th century