Siegfried I, Count of Sponheim

Siegfried I
Margrave of the Hungarian March
Count of Sponheim
Reignc. 1044–1065
PredecessorEberhard I
SuccessorEngelbert I
Bornc. 1010
Sponheim Castle, Nahegau, Rhenish Franconia
Died(1065-02-07)7 February 1065
Byzantine Bulgaria
BuriedSt. Paul's Abbey
Noble familyHouse of Sponheim
SpouseRichardis von Sponheim
Issue
FatherEberhard I von Spanheim
MotherHedwig, Countess of Nellenburg

Siegfried I (c. 1010 – 7 February 1065) is considered the progenitor of the Carinthian ducal House of Sponheim (Spanheimer) and all of its lateral branches, including the Counts of Lebenau and the Counts of Ortenburg. He is documented as Count of Sponheim from 1044 and served as margrave of the Hungarian March in 1045/46 and as count in the Puster Valley and the Lavant Valley from 1048 until his death.