Research Notes:

The Annales Kamenzenses record that "Mesco…rex Polanorum…sororem…Atleydem" married "Iesse rex Ungarie" by whom she was mother of "Stephanum regem Ungarie". The Breve chronicon Silesiæ names "Adilheidem" as sister of "primo dux Mesco", adding that she married "Jesse rex Ungarie" and that she was the mother of "Stephanum regem Ungarie" born in 975. The Kronika Węgiersko-Polska records that "Iesse" married "sororem Meschonis ducis…Athleitam", adding that she was a Christian and converted her husband to Christianity. The primary source which confirms her first marriage has not yet been identified. According to Europäische Stammtafeln, Adelajda was the daughter not sister of Mieszko I Prince of Poland, although the primary source on which this is based has not yet been identified. If this is correct, she was an otherwise unrecorded daughter by his first wife (name not known), assuming that Prince Mieszko's marriage to Dobroslawa of Bohemia is correctly dated to 965. Adelajda's birth date range is estimated from the supposed dates of birth of her two sons by her first husband (before his death in [976/78]) and of her three known daughters by her second marriage after [985]. The date range appears chronologically more consistent with her having been the daughter, rather than sister, of Mieszko, but this would be in direct contradiction to the sources quoted above. If she was Mieszko's sister, it is likely that they did not share the same mother, assuming that the estimated birth dates of Mieszko and Adelajda are both accurate. It is probable that her second marriage was arranged in accordance with the Magyar tradition that the oldest male relative should marry the widow of a deceased relative (originally polygamously) and take care of his children. ¹