Sviatoslav ' s invasion of Bulgaria Sviatoslav ' s invasion of Bulgaria refers to a conflict beginning in 967 / 968 and ending in 971 , carried out in the eastern Balkans , and involving the Kievan Rus ' , Bulgaria , and the Byzantine Empire . The Byzantines instigated the Rus ' ruler Sviatoslav to attack Bulgaria , leading to the collapse of the Bulgarian state and the occupation of much of the country by the Rus ' . The allies then turned against each other , and the ensuing military confrontation ended with a Byzantine victory . The Rus ' withdrew and eastern Bulgaria was incorporated into the Byzantine Empire . In 927 , a peace treaty was signed between Bulgaria and Byzantium ending many years of warfare and establishing forty years of peace . Both states prospered during this interlude , but the balance of power gradually shifted in favour of the Byzantines , who made great territorial gains against the Abbasid Caliphate in the East and formed a web of alliances surrounding Bulgaria . By 965 / 966 , the warlike new Byzantine emperor Nikephoros II Phokas refused to renew the annual tribute that was part of the peace agreement and declared war on Bulgaria . Preoccupied with his campaigns in the East , Nikephoros resolved to fight the war by proxy and invited the Rus ' ruler Sviatoslav to invade Bulgaria . Sviatoslav ' s subsequent campaign greatly exceeded the expectations of the Byzantines , who had regarded him only as a means to exert diplomatic pressure on the Bulgarians . The Rus ' prince conquered the core regions of the Bulgarian state in 967 – 969 , seized the Bulgarian tsar Boris II , and ruled the country through him . Sviatoslav intended to continue his drive south against Byzantium itself , which in turn regarded the establishment of a new and powerful Russo - Bulgarian state in the Balkans with great concern . After stopping a Rus ' advance through Thrace at Arcadiopolis in 970 , the Byzantine emperor John I Tzimiskes led an army north into Bulgaria in 971 and captured Preslav , the capital . After a three - month siege of the fortress of Dorostolon , Sviatoslav agreed to terms with the Byzantines and withdrew from Bulgaria . Tzimiskes formally annexed Eastern Bulgaria to the Byzantine Empire . However , most of the country in the central and western Balkans remained in effect outside imperial control ; this would lead to the revival of the Bulgarian state in these regions under the Cometopuli dynasty . Background . By the beginning of the 10th century , two powers had come to dominate the Balkans : the Byzantine Empire controlled the south of the peninsula and the coasts , and the Bulgarian Empire held the central and northern Balkans . The early decades of the century were dominated by Tsar Simeon ( r . 893 – 927 ) , who expanded his empire at Byzantium ' s expense in a series of wars and secured for himself recognition of his imperial title . Simeon ' s death in May 927 was soon followed by a rapprochement between the two powers , formalized with a treaty and a marriage alliance later that same year . Simeon ' s second son and successor , Peter I ( r . 927 – 969 ) , married Maria , the grand - daughter of the Byzantine emperor Romanos I Lekapenos ( r . 920 – 944 ) , and his imperial title was recognized . An annual tribute ( which the Byzantines termed a subsidy for Maria ' s upkeep , to save face ) was agreed to be paid to the Bulgarian ruler in exchange for peace . The agreement was kept for almost forty years as peaceful relations suited both sides . Bulgaria , despite the barrier formed by the Danube , was still menaced in its northern reaches by steppe peoples , the Magyars and the Pechenegs . They launched raids throughout Bulgaria , occasionally reaching Byzantine territory as well . The Byzantine – Bulgarian peace nevertheless meant less trouble from the north , as many Pecheneg raids had been sponsored by the Byzantines . Peter ' s reign , although lacking the military splendour of Simeon ' s , was still a " golden age " for Bulgaria , with a flourishing economy and a thriving urban society . Byzantium used the peace to focus its energy on wars against the Abbasid Caliphate in the East , where a series of campaigns under generals John Kourkouas and Nikephoros Phokas greatly expanded imperial territory . At the same time , military reforms created a much more effective and offensively - oriented army . The Byzantines did not neglect the Balkans , working steadily to improve their contacts with the peoples of central and eastern Europe , subtly altering the balance of power in the peninsula . Their Crimean outpost of Cherson maintained trade with the Pechenegs and the emerging power of the Kievan Rus ' ; Byzantine missionaries led the Christianization of the Magyars ; and the Slavic princes of the western Balkans came to once again acknowledge the suzerainty of the Empire , particularly after Caslav Klonimirovic ended Bulgarian control over Serbia . These relationships on the periphery of the Bulgarian Empire were an important asset for Byzantine diplomacy : instigating attacks against Bulgaria by the Pechenegs and the Khazars was a time - honoured method of applying pressure on the Bulgarians . Upon the sudden death of Emperor Romanos II in 963 , Nikephoros Phokas usurped the throne from Romanos ' infant sons and became senior emperor as Nikephoros II ( r . 963 – 969 ) . Nikephoros , a prominent member of the Anatolian military aristocracy , also focused mostly on the East , leading his army personally in campaigns that recovered Cyprus and Cilicia . Thus things stood when a Bulgarian embassy visited Nikephoros in late 965 or early 966 to collect the tribute owed . Nikephoros , his confidence boosted by his recent successes , and deeming the Bulgarian ruler ' s demand presumptuous , refused to pay , claiming that with Empress Maria ' s recent death ( ca . 963 ) any such obligations had ceased . He had the envoys beaten and sent them home with threats and insults . He proceeded with his troops to Thrace , where he staged an elaborate parade as a display of military strength and sacked a few Bulgarian border forts . Nikephoros ' decision to effect a breach of relations with Bulgaria was also in response to the recent treaty that Peter I had signed with the Magyars . The treaty stipulated that the Magyars would be allowed to pass through the country and raid Byzantium in exchange for halting their raids in Bulgaria . Anxious to avoid war , Tsar Peter sent his two sons , Boris and Roman , as hostages to Constantinople . This move failed to appease Nikephoros , but he was not able or willing to campaign against Bulgaria ; his forces were engaged in the East , and furthermore , drawing on the Byzantines ' past experience , Nikephoros was reluctant to mount an expedition into the mountainous and heavily forested terrain of Bulgaria . Consequently he resorted to the old Byzantine expedient of calling in a tribe from eastern Europe to attack Bulgaria . In late 966 or early 967 , he dispatched the " patrikios " Kalokyros , a citizen of Cherson , as his ambassador to Sviatoslav , ruler of the Rus ' . The Byzantines had long maintained close relations with the Rus ' , with whom they were bound by treaty . With promises of rich rewards and , according to Leo the Deacon , a payment of 1 , 500 pounds of gold , the Rus ' ruler was induced to attack Bulgaria from the north . That Nikephoros should call upon Sviatoslav for aid was unusual , since the Pechenegs were traditionally used for such tasks . The historian A . D . Stokes , who examined the questions surrounding the background and chronology of Sviatoslav ' s Bulgarian campaign , suggested that this move had a second motive of turning the attention of Sviatoslav , who had recently destroyed the Khazar khanate , away from the Byzantine outpost of Cherson . Sviatoslav enthusiastically agreed to the Byzantine proposal . In August 967 or 968 , the Rus ' crossed the Danube into Bulgarian territory , defeated a Bulgarian army of 30 , 000 men in the Battle of Silistra , and occupied most of the Dobruja . According to the Bulgarian historian Vasil Zlatarski , Sviatoslav seized 80 towns in northeastern Bulgaria . They were looted and destroyed but not permanently occupied . Tsar Peter I suffered an epileptic stroke when he received news of the defeat . The Rus ' wintered at Pereyaslavets , while the Bulgarians retreated to the fortress of Dorostolon ( Silistra ) . The next year , Sviatoslav left with part of his army to counter a Pecheneg attack on his capital at Kiev ( incited either by the Byzantines or , according to the Russian " Primary Chronicle " , by the Bulgarians ) . At the same time , Tsar Peter sent a new embassy to Byzantium , a visit that was recorded by Liutprand of Cremona . In contrast to their previous reception , this time the Bulgarian envoys were treated with great honour . Nevertheless , Nikephoros , confident of his position , demanded harsh terms : Tsar Peter was to resign and be replaced by Boris , and the two young emperors , Basil and Constantine , were to be married to Bulgarian princesses , daughters of Boris . Peter retired to a monastery , where he died in 969 , while Boris was released from Byzantine custody and recognized as Tsar Boris II . For the moment , it appeared that Nikephoros ' plan had worked . However , Sviatoslav ' s brief sojourn into the south awakened in him the desire to conquer these fertile and rich lands . In this intention he was apparently encouraged by the former Byzantine envoy , Kalokyros , who coveted the imperial crown for himself . Thus , after defeating the Pechenegs , he set up viceroys to rule Russia in his absence and turned his sights southward again . In summer 969 , Sviatoslav returned to Bulgaria in force , accompanied by allied Pecheneg and Magyar contingents . In his absence , Pereyaslavets had been recovered by Boris II ; the Bulgarian defenders put up a determined fight , but Sviatoslav stormed the city . Thereafter Boris and Roman capitulated , and the Rus ' rapidly established control over eastern and northern Bulgaria , placing garrisons in Dorostolon and the Bulgarian capital of Preslav . There Boris continued to reside and exercise nominal authority as Sviatoslav ' s vassal . In reality he was little more than a figurehead , retained in order to lessen Bulgarian resentment at and reaction to the Rus ' presence . Sviatoslav appears to have been successful in enlisting Bulgarian support . Bulgarian soldiers joined his army in considerable numbers , tempted partly by the prospects of booty , but also enticed by Sviatoslav ' s anti - Byzantine designs and probably mollified by a shared Slavic heritage . The Rus ' ruler himself was careful not to alienate his new subjects : he forbade his army from looting the countryside or plundering cities that surrendered peacefully . Thus Nikephoros ' scheme had backfired : Instead of a weak Bulgaria , a new and warlike nation had been established at the Empire ' s northern border , and Sviatoslav showed every intention of continuing his advance south into Byzantium . The emperor tried to get the Bulgarians to resume the war against the Rus ' , but his proposals were not heeded . Then , on 11 December 969 , Nikephoros was murdered in a palace coup and succeeded by John I Tzimiskes ( r . 969 – 976 ) , to whom fell the task of dealing with the situation in the Balkans . The new emperor sent envoys to Sviatoslav , proposing negotiations . The Rus ' ruler demanded a huge sum before he would withdraw , insisting that otherwise the Empire should abandon its European territories to him and withdraw to Asia Minor . For the time being , Tzimiskes was preoccupied with consolidating his position and countering the unrest of the powerful Phokas clan and its adherents in Asia Minor . He therefore entrusted the war in the Balkans to his brother - in - law , the Domestic of the Schools Bardas Skleros , and to the eunuch stratopedarch Peter Phokas . In early 970 , a Rus ' army , with large contingents of Bulgarians , Pechenegs , and Magyars , crossed the Balkan Mountains and headed south . The Rus ' stormed the city of Philippopolis ( now Plovdiv ) , and , according to Leo the Deacon , impaled 20 , 000 of its surviving inhabitants . Skleros , with an army of 10 , 000 – 12 , 000 men , confronted the Rus ' advance near Arcadiopolis ( now Luleburgaz ) in early spring 970 . The Byzantine general , whose army was considerably outnumbered , used a feigned retreat to draw the Pecheneg contingent away from the main army into a prepared ambush . The main Rus ' army panicked and fled , suffering heavy casualties at the hands of the pursuing Byzantines . The Rus ' withdrew north of the Balkan mountain range , which gave Tzimiskes time to deal with internal unrest and to assemble his forces . Byzantine offensive . After being occupied with suppressing the revolt of Bardas Phokas throughout the year 970 , Tzimiskes marshalled his forces in early 971 for a campaign against the Rus ' , moving his troops from Asia to Thrace and gathering supplies and siege equipment . The Byzantine navy accompanied the expedition , tasked with carrying troops to effect a landing in the enemy ' s rear and to cut off their retreat across the Danube . The emperor chose Easter week of 971 to make his move , catching the Rus ' completely by surprise : The passes of the Balkan mountains had been left unguarded , either because the Rus ' were busy suppressing Bulgarian revolts or perhaps ( as A . D . Stokes suggests ) because a peace agreement that had been concluded after the battle of Arcadiopolis made them complacent . The Byzantine army , led by Tzimiskes in person and numbering 30 , 000 – 40 , 000 , advanced quickly and reached Preslav unmolested . The Rus ' army was defeated in a battle before the city walls , and the Byzantines proceeded to lay siege . The Rus ' and Bulgarian garrison under the Rus ' noble Sphangel put up a determined resistance , but the city was stormed on 13 April . Among the captives were Boris II and his family , who were brought to Constantinople along with the Bulgarian imperial regalia . The main Rus ' force under Sviatoslav withdrew before the imperial army towards Dorostolon on the Danube . As Sviatoslav feared a Bulgarian uprising , he had 300 Bulgarian nobles executed , and imprisoned many others . The imperial army advanced without hindrance ; the Bulgarian garrisons of the various forts and strongholds along the way surrendered peacefully . As the Byzantines neared Dorostolon , they came upon the Rus ' army , which had deployed on a field before the city , ready for battle . After a long and bitter struggle , the Byzantines won the day when Tzimiskes ordered his heavy cataphract cavalry to advance . The Rus ' quickly broke ranks and fled inside the fortress . The subsequent siege of Dorostolon lasted for three months , during which the Byzantines blockaded the city by land and sea and the Rus ' attempted several sallies . Three pitched battles were fought , all of which ended in Byzantine victories . After the final and particularly savage battle in late July , the Rus ' were forced to capitulate . According to Byzantine chroniclers , by that time only 22 , 000 out of an army of originally 60 , 000 remained . Tzimiskes and Sviatoslav met and agreed to a peace treaty : The Rus ' army was allowed to depart , leaving their captives and plunder behind , and their trading rights were re - affirmed in exchange for an oath to never again attack imperial territory . Sviatoslav would not long outlive the peace settlement , as he was slain on his way home in a Pecheneg ambush at the river Dnieper . Aftermath . The outcome of the war was a complete Byzantine victory , and Tzimiskes decided to take full advantage . Although he initially recognized Boris II as the legitimate Bulgarian tsar , after the fall of Dorostolon his intentions changed . This became evident during his triumphal return to Constantinople , where the emperor entered the Golden Gate behind a wagon carrying an icon of the Virgin Mary as well as the Bulgarian regalia , with Boris and his family following behind Tzimiskes . When the procession reached the Forum of Constantine , Boris was publicly divested of his imperial insignia , and at the church of Hagia Sophia , the Bulgarian crown was dedicated to God . This marked the symbolic end of Bulgaria as an independent state , at least in Byzantine eyes . Byzantine generals were installed in the eastern parts of the country along the Danube . Preslav was renamed Ioannopolis in honour of the emperor , and Dorostolon ( or perhaps Pereyaslavets ) was renamed Theodoropolis after St . Theodore the Stratelate , who was believed to have intervened in the final battle before Dorostolon . Tzimiskes reduced the Bulgarian patriarchate to an archbishopric subject to the Patriarch of Constantinople . He brought the Bulgarian royal family and many nobles to live in Constantinople and Asia Minor , while the region around Philippopolis was settled with Armenians . However , outside eastern Bulgaria , and there only in the major urban centres , Byzantine control existed only in theory . Tzimiskes , like Nikephoros Phokas , was more interested in the East . With the Rus ' threat banished and Bulgaria seemingly pacified , his attention turned to Syria . No coordinated Byzantine drive to secure the interior of the Balkans was made . As a result the north - central Balkans and Macedonia , where neither the Rus ' nor Tzimiskes ' troops had ventured , remained as before in the hands of the local Bulgarian elites . In these areas , a Bulgarian resistance emerged , taking advantage of the Byzantine civil wars after the death of Tzimiskes in 976 , led by the four sons of a count ( " comes " ) Nicholas , who became known as the " Cometopuli " ( " sons of the count " ) . The most capable amongst them , Samuel , revived the Bulgarian realm , now centered in Macedonia , and was crowned Tsar in 997 . A formidable warrior , he led raiding campaigns into Byzantine territory as far south as the Peloponnese , and he engaged the Byzantine emperor Basil II ( r . 976 – 1025 ) in a series of wars resulting in the final conquest of the Bulgarian state by the Byzantines in 1018 . Nevertheless , due to the events of 971 , the Byzantines would never regard him as anything other than a rebel against imperial authority , let alone concede the principle of equality enjoyed by the Bulgarian rulers before 971 .