Agatha

There is no primary evidence for Agatha's ancestors from XI. and XII. century. The sources from that time are contradictory, no two agreeing completely.

There are several different theories about Agatha's parents. None of them has gained widespread acceptance by experts.

Unknown Origin

There is some confusion regarding her parentage. The Anglo-Saxon Chronicle says that she was a niece of the Emperor Henry (filia germani imperatoris Henrici). Florent of Worcester says Agatha was the daughter of a brother of Emperor Henry. William of Malmesbury says Agatha was sister of a queen of Hungary. Roger of Hoveden (late 12th century) says that Agatha was a Russian princess. Several other chroniclers say that Agatha was the daughter of a king of Hungary. A traditional theory is that she was the daughter of Henry II's brother.

Ronay and Vajay suggest that she might have been the daughter of Liudolf, Margrave of West Friesland, a half-brother of the Emperor Henry III who is known to have been a close relative of Agatha. Jette argues for Yaroslav I, Grand Duke of Kiev, and Ingegarde of Sweden. De Vajay's hypothesis makes Agatha a daughter of a half-brother of Emperor Henry III, consistent with early documents which specify that Agatha was "filia germani imperatoris Henrici, " that is, daughter of a brother of the Emperor Henry. Jette believes that this hypothesis requires an unreasonably tight chronology and that the absence of mention of such a connection by continental chroniclers makes it suspect. In response, it can be said that the chronology -- three generations in 58 years -- is tight but not impossible.

Edward was a political non-entity on the continent, so the absence of a mention is not surprising. Jette also adduces onomastic support for his proposal that Jaroslav and Ingegarde were the parents of Agafiya (a Greek name). Jaroslav had an attraction to Greek culture, perhaps inspired by his stepmother Anne of Byzantium; in addition, none of Agafiya's children or grandchildren were given German names, while two of her three children (Margaret and Christine) had Greek names which are found only in Sweden at this time. Jette believes that the blood relationship with Emperor Henry might have been inferred by later chroniclers from William of Malmesbury's statement that Agafiya was the sister of the Queen of Hungary. Jette's hypothesis makes Agafiya a sister of Anastasia, queen of Andrew I of Hungary. De Vajay's hypothesis makes Agafiya a niece of Judith, daughter of Emperor Henry III and wife of Andrew's son Salomon. Another hypothesis is that she was daughter of Vazul of Hungary, which would make her a granddaughter of Agatha Chryselia.

Wikipedia

Origin
Medieval sources

Ailred of Rievaulx, who likely received his information from David, King of Scotland, Agatha's grandson. Agatha's origin is alluded to in numerous surviving medieval sources, but the information they provide is sometimes imprecise, often contradictory, and occasionally demonstrably false. The earliest surviving source, the Anglo-Saxon Chronicle, along with John of Worcester's Chronicon ex chronicis and its associated genealogical tables (sometimes named separately as Regalis prosapia Anglorum), Symeon of Durham (thaes ceseres maga) and Ailred of Rievaulx describe Agatha as a kinswoman of an "Emperor Henry", the latter explicitly making her daughter of his brother (filia germani imperatoris Henrici). It is not clear whether the "Henry" mentioned was Henry II, Holy Roman Emperor or Henry III, Holy Roman Emperor, although John of Worcester in Regalis prosapia Anglorum specifies Henry III.

Later sources of dubious credibility such as the Chronicle of Melrose Abbey call her daughter of Henry, while Matthew of Paris calls her the emperor's sister (soror Henrici imperatoris Romani). Geoffrey Gaimar in Lestoire des Engles states that she was daughter of the Hungarian king and queen (Li reis sa fille), although he places the marriage at a time when Edward is thought still to have been in Kiev, while Orderic Vitalis in Historiae Ecclesiasticae is more specific, naming her father as king Solomon (filiam Salomonis Regis Hunorum), even though he was actually a contemporary of Agatha's children. William of Malmesbury in De Gestis Regis Anglorum states that Agatha's sister was a Queen of Hungary (reginae sororem) and is echoed in this by Alberic of Trois-Fontaines, while, less precisely, Ailred says of Margaret that she was derived from English and Hungarian royal blood (de semine regio Anglorum et Hungariorum extitit oriunda).

Finally, Roger of Howden and the anonymous Leges Edwardi Confessoris indicate that while Edward was a guest of Kievan "king Malesclodus" he married a woman of noble birth (nobili progenio), Leges adding that the mother of St Margaret was of Rus royal blood (ex genere et sanguine regum Rugorum).

http://en.wikipedia.org/wiki/Agatha,_wife_of_Edward_the_Exile

https://www.medievalists.net/2014/01/reconsidering-agatha-wife-of-e...

http://genealogy.euweb.cz/note/agatha.html