Bolesław I the Brave was a seminal figure in Polish history, ascending as Duke of Poland from 992 until his elevation to the first King of Poland in 1025. He briefly held the title of Duke of Bohemia as Boleslaus IV between 1003 and 1004. A descendant of the Piast dynasty, Bolesław was recognized as a skilled ruler and a key player in Central European politics. His reign was marked by his efforts to spread Western Christianity and his pivotal role in raising Poland to the status of a kingdom.

Bolesław was the son of Mieszko I and his first wife, Dobrawa of Bohemia. During the latter years of his father’s reign, he ruled Lesser Poland and, following Mieszko's death in 992, quickly moved to consolidate power by unifying the country, sidelining his stepmother Oda of Haldensleben, and neutralizing his half-brothers and their factions by 995. His reign was distinguished by his devout Christian faith and support for the missionary work of figures like Adalbert of Prague and Bruno of Querfurt.

The martyrdom of Adalbert in 997 significantly advanced Bolesław’s agenda, leading him to successfully negotiate for the bishop’s remains, which he purchased with their weight in gold, affirming Poland's independence from the Holy Roman Empire. This was further solidified during the Congress of Gniezno on 11 March 1000, where Emperor Otto III granted Poland an autonomous church structure with a metropolitan see in Gniezno and additional bishoprics in Kraków, Wrocław, and Kołobrzeg. At this congress, Bolesław formally ceased tribute payments to the Empire.

After Otto III's death in 1002, Bolesław engaged in several conflicts with Otto's successor, Henry II, which concluded with the Peace of Bautzen in 1018. That same year, Bolesław led a successful military campaign to Kiev, installing his son-in-law Sviatopolk I as ruler, an event celebrated in legend by his purported chipping of his sword on Kiev's Golden Gate, inspiring the name of the Polish coronation sword, Szczerbiec.

Bolesław I’s reign was characterized by extensive military campaigns and territorial expansion that included modern-day Slovakia, Moravia, Red Ruthenia, Meissen, Lusatia, and Bohemia. He also established significant legal and economic foundations, such as the "Prince's Law," and oversaw the construction of key infrastructures like churches, monasteries, and forts. He introduced the grzywna, the first Polish monetary unit, which was divided into 240 denarii, and initiated the minting of his own coins. His strategic and developmental initiatives significantly elevated Poland’s status, aligning it with other established Western monarchies and enhancing its stature in Europe.