BOLESLAV I., called "Chrobry" (the Mighty), king of Poland (reigned 992-1025), was the son of Mieszko, first Christian prince of Poland, and the Bohemian princess Dobrawa, or Bona, whose chaplain, Jordan, converted the court from paganism to Catholi cism. He succeeded his father in 992. A born warrior, he raised the little struggling Polish principality on the Vistula to the rank of a great power. In 996 he gained a seaboard by seizing Pom erania, and then took advantage of the troubles in Bohemia to occupy Cracow, previously a Czech city. At Gnesen Boleslav in the year loon entertained Otto III. so magnificently that the emperor is said to have given him the title of king, though 25 years later, in the last year of his life, Boleslav thought it neces sary to crown himself king a second time. He still remained a vassal of the empire, but ecclesiastically Poland was independent when Gnesen became a metropolitan see by the favour of Pope Sylvester II. On the death of Otto, Boleslav invaded Germany, penetrated to the Elbe, occupying Stralsund and Meissen on his way, and extended his dominions to the Elster and the Saale. Henry II., however, at the diet of Merseburg, declined the money offered by Boleslav for the retention of Meissen, and from that time Boleslav was the enemy of the German king. He seized the opportunity of a revolt in Bohemia to intervene there to re-estab lish his cousin Boleslav the Red as duke, then enticed him to Poland, caused him to be blinded, and got the Bohemians to ac cept himself as duke. He found allies against Henry in Germany itself, and then, in 1004, attacked Bavaria, but without much success. His German allies sought Henry's pardon. On Henry's return from his Italian expedition he marched against Boleslav, who was expelled from Prague and made peace in 1005. A third Polish war ended in 1018 by the peace of Bautzen, greatly to the advantage of Boleslav, who retained Lusatia. He then turned his arms against Jaroslav, grand duke of Kiev, whom he routed on the banks of the Bug, then the boundary between Russia and Poland. At his death in 1025 he left Poland one of the mightiest states of Europe, extending from the Bug to the Elbe, and from the Baltic to the Danube, and possessing besides the overlordship of Russia.
See J. N. Pawlovski, St. Adalbert (Danzig, 186o) ; Chronica Nestoris (Vienna, 186o) ; Heinrich R. von Zeissberg, Die Kriege Kaiser Heinrichs II. mit Herzog Boleslaw I. (1868).