There is no exact record of when the Principality was formed, meaning it was likely an evolutionary process. In 892 Polotsk was first mentioned in the Primary Chronicle as a town within the realm of the Novgorod Rus, alongside Murom and Beloozero. Initially Polotsk was ruled by a local dynasty, and not an appointed governor from Kiev. This sentiment of home rule remained in Polotsk, which considered itself an independent nation rather then a part of the greater Rus state. In addition, Polotsk was not home solely to East Slavs, but also an older people referred to as the Krivichi. This culture would later be absorbed into Polotsk and disappear.
The second time Polotsk was mentioned in the chronicle, in 980, its ruler was the Varangian warlord Rogvold, later referred to as Rogvold the Wise and the first independent Prince of Polotsk, whose descendants claimed was a part of the Ynglings royal family from Scandinavia. Rogvold was an active player in the power struggles of the Rus; in the late 10th century, Polotsks estimated population reached six thousand, which provided a significant army.
In 972 the reigning prince of Kiev, Sviatoslav I, died. His sons, Vladimir of Novgorod and Yaropolk of Kiev, both sought Polotsk's help against the other in attempt to claim the throne of the Rus. To attempt to do this, Vladimir sought Rogneda, the daughter of Rogvold, as his wife. Rogneda wished to refuse, but Rogvold feared that if she did, Vladimir would turn his armies to Polotsk and take her by force. To attempt to give himself some time, he sent Vladimir away, telling him Rogneda would answer him in one month. Vladimir grudgingly accepted; he assumed incorrectly that this time was needed to gather a dowry.
In reality, Rogvold sent word to Yaropolk, telling of Vladimir's marriage proposal. Yaropolk launched a marriage proposal of his own. Rogvold said that he must come to Polotsk itself and ask Rogneda personally if she was to agree to marry him. Vladimir entered the city with his delegation in late 973; a few days earlier, Yaropolk had been smuggled in.
Both Princes were told that Rogneda would meet them in a wooden building built specifically for that purpose. After both princes entered from different sides, the doors were discreetly locked by Rogvold's guards. Both princes and their delegations, upon seeing each other, let out a great cry, thinking their opponent had come to assassinate them. They drew their swords and proceeded to fight. Rogvold, watching from the one window in the building, ordered it torched. In the chaos of the fire, both Princes and claimants to the throne of the Rus were slain; some sources state that Vladimir killed Yaropolk in personal combat.
Without the princes, the Rus fell into disarray. Numerous new claimants appeared, creating a decades long civil war that historians would call the Bohna Xaoc, or "Chaotic War". Many of the Rus tributary states broke away; in particular, Khazaria faced a sudden and dramatic revival to the south.Rogvold refused to allow Polotsk to become involved the struggle. After a decade of struggle, the Principality of Chernigov becomes the nominal winner. Although they become the first to formally hold the Kingdom of Russia, Polotsk and Novgorod's armies remained undefeated, and their respective lords unsubmissive. The self-proclaimed Oleg I of Russia marched on Minsk in the spring of 984 after Rogvold's successor Yaroslav refused to pay tribute and acknowledge Oleg as his king. In the battle that followed, Yaroslav's forces, numbering roughly six thousand strong, bested Oleg's superior armies with relatively few casualties, ensuring Polotski independence for the years to come. Oleg retreated to Kiev, licking his wounds, but would never again attack Polotsk. Instead, he invaded Novgorod, sacking the city before retreating for the winter. In the end, the man who conquered Russia would never unite it. Facing revolts at home, Oleg's realm would never include either of the rogue principalities. Instead, he would be forced to deal with Khazar incursions and internal strife until his death in 996.
Yaroslav's reign was long and prosperous. He died in 1000, and was succeeded by his son Bryachislav. Bryachislav, later referred to as the Pious, had the formal appearance of a pagan; however, he had in fact converted to Catholicism a few years prior to assuming his reign through a Polish missionary. Bryachislav, however, went the first twenty years of his reign without the knowledge of his faith becoming common knowledge.
Bryachislav warred periodically with the Selonians, a tribe inhabiting between the Letigallians and the Lithuanians. Between these wars, he systematically empowered Christians within his own realm. The Selonians would lose half their realm to Byrachislav's conquests, and thanks to his efforts, large swaths of it would be christian.Bryachislav invaded Novgorod in 1019, but made only minor gains before the winter rose and peace was concluded. On his return, however, his realm was in celebration. His minor victory was greatly exaggerated in the public mind, and Byrachislav was the most beloved man in Polotsk, at least among the nobles. This was due in part to Christian orators, who portrayed Bryachislav as a heroic figure. Bryachislav took the moment of intense loyalty of his subjects as an opportunity. He declared that Polotsk was officially a catholic nation, and mandated that the entire nation convert to Christianity. Although not popular, the majority of the population enthusiastically converted to the faith that Byrachislav claimed made him invincible on the battlefield. Several groups, however, were not so enthusiastic, and launched small-scale rebellions against Bryachislav. The prince of Polotsk responded by burning the heathens at the stake; around this time, he commissioned the Polotsk Banner, the first flag of Polotsk. Bryachislav was both feared and beloved; for the rest of his reign he would do little else then strengthen Catholicism's hold over Polotsk.
Expansion into Livonia
Byrachislav's son Ivan did little to expand the realm of Polotsk. His reign, however, brought stability and economic prosperity; factors which sped up the conversion of the populace to Christianity, and bought Ivan freedom from what was a major threat of internal struggle. Ivan's reign is barely recorded by the Primary Chronicle, but his efforts allowed Polotsk to keep the considerable gains it had made in the past.
Ivan's son, Byrachislav II, was of a more militaristic mindset. Byrachislav was forced to spend the early years of his reign fighting pagan rebellions, but in this time gained the complete loyalty of his nobles and their armies. Under his reign, the last Selonians were conquered. Byrachislav also made several expeditions against the Latigallans, and succeeded in breaking their ability to raid his realm. Byrachislav's success was largely based upon Christianization programs which bound the local Selonians to his rule, and his relentless abandon when it came to military matters. Rumors of his ruthlessness and the slaughter his troops gave at the slightest provocation is thought to have inspired several folktales which persist to this day.