Boleslaw I the Brave vs Cnut the Great

Bolesław I supported the missionary work of Bishop Adalbert of Prague, who was martyred by the Prussians. Bolesław ransomed Adalbert's body and buried it in Gniezno. This event elevated Adalbert to sainthood and led to the establishment of the Archbishopric of Gniezno.

Holy Roman Emperor Otto III visited Gniezno for a congress with Boles

Bolesław I intervened in the Kievan Rus' succession crisis, capturing Kiev and installing his son-in-law Sviatopolk I as Grand Prince. He annexed the Cherven Cities (Red Ruthenia) into Poland, expanding Polish territory eastward. The campaign demonstrated Polish military power.

Bolesław I signed the Peace of Bautzen with Holy Roman Emperor Henry II, ending a series of wars over Lusatia and Meissen. The treaty confirmed Polish control over Lusatia and Milsko, securing Poland's western borders and recognizing Bolesław's territorial gains.

Bolesław I was crowned King of Poland in Gniezno, becoming the first crowned king of the Polish state. This coronation elevated Poland from a duchy to a kingdom, establishing its sovereignty and status in medieval Europe. He died shortly after the coronation.

After defeating Edmund Ironside at Assandun and Edmund's death, Cnut became sole king of England. He divided the kingdom into four earldoms: Wessex, Mercia, Northumbria, and East Anglia.

Cnut succeeded his brother Harald II as king of Denmark. He now ruled both England and Denmark, creating a North Sea empire.

Cnut traveled to Rome for the coronation of Holy Roman Emperor Conrad II. He secured agreements for reduced tolls for English pilgrims and merchants traveling through Europe.

Cnut invaded Norway and defeated King Olaf Haraldsson at the Battle of Stiklestad. Olaf was killed, and Cnut added Norway to his domains, becoming ruler of a North Sea empire.

Cnut died at Shaftesbury in Dorset on November 12, 1035. His death led to the disintegration of his North Sea empire, with his sons Harold Harefoot and Harthacnut contesting the English throne.