Martha Eriksdotter (Märta Bonde) is supposed to have been the daughter of Erik X, King of Sweden. However, her existence has been doubted by modern Swedish historians, and she can have been made up by Charles VIII or his chroniclers to provide him with a more impressive background.
She was supposed to have married Nils Sixtensson Sparre, a Marshal in Sweden. Martha’s paternity and her marriage are recorded in the book “Anteckningar om svenska qvinnor” by PG Berg and Wilhelmina Stålberg,Page 274.
The title of the book roughly translated: Notes on Swedish women. (A biographical dictionary from 1864, covering only Swedish women.)
In Swedish the page reads:
Märtha, dotter af Erik X, som blef gift med Nils Sixtensson till Tofta, och, genom detta äktenskap, stammoder för Sparre- och Oxenstjerna-slägterna.
Engilsh translation:
Martha, daughter of Erik X, who was married to Nils Sixtensson of Tofta, and, through this marriage a progenitress strain for the Sparre and Oxenstjerna-race.