 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").