Mieszko I of Poland and half a century later, by Bishop Thietmar of Merseburg. By the time Mieszko I took over from his father, the Polans' tribal federation of Greater Poland had for some time been actively expanding. Continuing this process, perhaps in the first years of Mieszko's reign, if it had not been done already by his father, Mieszko I conquered Masovia. Likely also during that period or earlier, at least partially Gdańsk Pomerania was obtained. Mieszko's interests were then concentrated mainly on areas occupied by the eastern (near the Oder River) branches of the Polabian Slavs; some of them became soon subordinated
Mieszko I of Poland another daughter of Mieszko, married to a Pomeranian Slavic Prince; she could be a daughter of Dobrawa or of one of the previous pagan wives. Also, a theory exists (apparently based on Thietmar and supported by Oswald Balzer in 1895) that Vladivoj, who ruled as Duke of Bohemia in 1002–1003, was a son of Mieszko and Dobrawa. Although most modern historians reject this claim, Bohemian historiography supported the Piast parentage of Vladivoj. In 978/79, Mieszko married Oda of Haldensleben (b. 955/60 – d. 1023), daughter of Dietrich of Haldensleben, Margrave of the Northern March. She was abducted by her future