Mieszko I of Poland by him. As Widukind of Corvey wrote, Mieszko ruled over the tribe called the "Licicaviki", now commonly identified with the Polabian Lubusz Land. Having the control over those more western (in respect to the original homeland of the Polans) tribes, Mieszko had entered the German sphere of influence. In 963 the German Margrave Gero conquered territories occupied by the Polabian Lusatian and Słupian tribes, and as a result came into direct contact with the Polish state. At the same time (about 960) Mieszko I began his expansion against the Velunzani and Lutici tribes. The war was recorded by the chronicler
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,