Claim: Eberhard I was the first known count of the Sponheim, while Stephen I was neither the cousin nor brother of Siegfried, who was also a Count of Sponheim, as well as, Count in the Puster Valley and Margrave of the Hungarian March.
Evidence: Eberhard Stephan I (d. about 1080), probably a cousin or brother of Siegfried I The founder of the ducal branch was Count Siegfried I (1010–1065), a Ripuarian Frank by birth and retainer of the Salian emperor Conrad II.