He continued to proselytise Western Christianity among his subjects and raised Poland to the rank of a kingdom, thus becoming the first Polish ruler to hold the title of rex, Latin for king.

When the country became divided in 992, he banished his father's widow, Oda of Haldensleben, purged his half-brothers along with their adherents and successfully reunified Poland by 995.

The martyrdom of Adalbert in 997 and Bolesław's successful attempt to ransom the bishop's remains, paying for their weight in gold, consolidated Poland's autonomy from the Holy Roman Empire.

Bolesław conducted successful military campaigns to the west, south and east of his realm, and conquered territories in modern-day Slovakia, Moravia, Red Ruthenia, Meissen, Lusatia, and Bohemia.

[13][14] The contemporaneous Thietmar of Merseburg recorded that Mieszko left "his kingdom to be divided among many claimants", but Bolesław unified the country "with fox-like cunning"[15] and expelled his stepmother and half-brothers from Poland.

[20] One of them bore the inscription Vencievlavus, showing that he regarded his mother's uncle Duke Wenceslaus I of Bohemia as the patron saint of Poland.

[35][36] Otto III made a pilgrimage to Saint Adalbert's tomb in Gniezno, accompanied by Pope Sylvester II's legate, Robert, in early 1000.

[42] Unger, who had been the only prelate in Poland and was opposed to the creation of the archdiocese of Gniezno, was made bishop of Poznań, directly subordinated to the Holy See.

The law of God, newly introduced in these regions gains more strength from such acts of force than from any fast imposed by the bishopsDuring the time the Emperor spent in Poland, Bolesław also showed off his affluence.

[45] At the end of the banquets, he "ordered the waiters and the cupbearers to gather the gold and silver vessels ... from all three days' coursis, that is, the cups and goblets, the bowls and plates and the drinking-horns, and he presented them to the emperor as a toke of honor ... [h]is servants were likewise told to collect the wall-hangings and the coverlets, the carpets and tablecloths and napkins and everything that had been provided for their needs and take them to the emperor's quarters",[47] according to Gallus Anonymus.

[49][55][56] An illustrated Gospel, made for Otto III around 1000, depicted four women symbolising Roma, Gallia, Germania and Sclavinia as doing homage to the Emperor who sat on his throne.

[57] Within that framework, Poland, along with Hungary, was upgraded to an eastern foederatus of the Holy Roman Empire, according to historian Jerzy Strzelczyk.

[57] Coins struck for Bolesław shortly after his meeting with the emperor bore the inscription Gnezdun Civitas, showing that he regarded Gniezno as his capital.

[58][59] In 1000 Bolesław issued a law prohibiting hunting beavers[60] and created a office called "Bobrowniczy"[61] whose task was to enforce prince's ordinances.

[74] During the next part of the offensive King Henry retook Meissen and in 1005, his army advanced as far into Poland as the city of Poznań where a peace treaty was signed.

[74] As part of the treaty, Bolesław paid homage to King Henry for the March of Lusatia (including the town of Bautzen) and Sorbian Meissen as fiefs.

[80] Once the imperial forces crossed the river Oder, Bolesław sent a detachment of Moravian knights in a diversionary attack against the Eastern March of the empire.

[74] Taking advantage of the involvement of Czech troops, Bolesław ordered his son to invade Bohemia, where Mieszko met very little resistance.

[86] Also, Bolesław (then a widower) strengthened his dynastic bonds with the German nobility through his marriage with Oda, daughter of Margrave Eckard I of Meissen.

[88] Bolesław organised his first expedition east, to support his son-in-law Sviatopolk I of Kiev, in 1013, but the decisive engagements were to take place in 1018 after the Peace of Bautzen was already signed.

[97] However, independent German sources confirmed that after Henry II's death in 1024, Bolesław took advantage of the interregnum in Germany and crowned himself king in 1025.

[103] Wipo of Burgundy in his chronicle describes the event: [In 1025] Boleslaus [of the Slavic nation], duke of the Poles, took for himself in injury to King Conrad the regal insignia and the royal name.

Death swiftly killed his temerity.It is widely believed that Bolesław had to receive permission for his coronation from the newly-elected Pope John XIX.

[106] However, Rome also hoped for a potential alliance to defend itself from Byzantine Emperor Basil II, who launched a military expedition to recover the island of Sicily and could subsequently threaten the Papal States from the south.

[106] Stanisław Zakrzewski put forward the theory that the coronation had the tacit consent of Conrad II and that the pope only confirmed that fact.

[110] Chronicler Jan Długosz (and followed by modern historians and archaeologists) writes that Bolesław was laid to rest at the Archcathedral Basilica of St. Peter and St. Paul in Poznań.

Later, Gallus Anonymus, in Chapter 6 of his Gesta principum Polonorum, named the Polish ruler as Bolezlavus qui dicebatur Gloriosus seu Chrabri.

[9][116] Historian Manteuffel says that the marriage was arranged in the early 980s by Mieszko I who wanted to strengthen his links with the Saxon lords and to enable his son to succeed Rikdag in Meissen.

[116] Historian Marek Kazimierz Barański writes that Bolesław repudiated his first wife after her father's death in 985 which left the marriage without any political value.

[3] Emnilda exerted a beneficial influence on Bolesław, reforming "her husband's unstable character",[18] according to Thietmar of Merseburg's report.