Титмар Мерзебургский
Nothing is known about his first years of life. Świętopełk is only named in the chronicles of Thietmar of Merseburg; he was omitted in the document ""Dagome iudex" (ca. 991/92), which names his parents and full-brothers Mieszko and Lambert, a fact which indicates that he may have been dead by that time, in or before 991.