Mieszko I of Poland Denmark, Canute the Great's daughter and wife of Henry III, Holy Roman Emperor. The first Christian ruler of territories later called Poland, Mieszko I is considered the creator of the Polish state. He continued the policy of both his father and grandfather, who were rulers of the pagan tribes located in the area of present-day Greater Poland. Through both alliances and the use of military force, Mieszko extended ongoing Polish conquests and early in his reign subjugated Kuyavia and probably Gdańsk Pomerania and Masovia. For most of his reign, Mieszko I was involved in warfare for the control of Western
Mieszko I of Poland from the second part of the name *Dago-mierz, since the merger in pronunciation of "sz" with the devoiced "rz" which would appear in this position is quite recent. However, some historians believe that the word "Dagome" is a melding of two names: the Roman Catholic "Dago," for "Dagobert" (Mieszko's hypothetical baptismal name), and the Slavic "Me," for "Mieszko." The Latin word "iudex" ("judge") would be used in the meaning of "prince." Another interpretation is that "Dagome iudex" is a corruption of "Ego Mesco dux" ("I, Prince Mieszko"). Mieszko I took over the tribal rule after his father's death ca. 950–960,