Owing to his pride as stated by the chronicler Thietmar of Merseburg (he allegedly once refused the marriage of one of his kinswoman to a Slav "dog"), in 983 the Slavic Lutici and Hevelli tribes sacked the lands of the eastern bishoprics of Havelberg and Brandenburg and reverted to paganism.
It is reported by Thietmar of Merseburg that the castle would have been razed if not for Gunzelin's insistence that the Poles be allowed to depart freely and the castle preserved.
He was called the "glory of eastern Franconia" by his own cousin, the chronicler Thietmar of Merseburg.
In May 1017 Cunigunde was staying on the imperial estate of Kaufungen, when, according to Thietmar of Merseburg, she became seriously ill and vowed to found a monastery if she recovered.
The name of the river Spree was recorded by Thietmar of Merseburg as Sprewa (Middle German sprejen, sprewen, High German sprühen meaning to spray water).
Orchard points out that Adam's description of the temple has often been questioned "on several levels" and that Thietmar of Merseburg produced a considerably less detailed but similar account of sacrifices held in Lejre, Denmark earlier in the 11th century.
Thietmar was a son of Siegfried the Elder, count of Walbeck (d. 15 March 991), and was related to the family of the emperor Otto the Great, and Kunigunde (ca. 956–13 July 997), daughter Henry I the Bald, Count of Stade (House of Udonids).
He was a cousin of the contemporary bishop and historian Thietmar of Merseburg.
Merseburg | Thietmar of Merseburg | Siegfried, Count of Merseburg | Gunther, Margrave of Merseburg | Treaty of Merseburg | Thietmar, Count of Merseburg | Thietmar | Boso of Merseburg |
Świętopełk is only named in the chronicles of Thietmar of Merseburg; he was omitted in the document "Dagome iudex" (ca. 991/92), were are named his parents and full-brothers Mieszko and Lambert, a fact who indicated that he maybe was dead by that time, in or before 991.