Balderas was the son of Ramón I de Urgel but his mother is unknown. The date and place of his birth have not been found.
Balderas de Urgel
Ramón I de Urgel (->1117)
Miró II de Urgel (->1079)
Guillermo I de Urgel (-1035)
Sancha
Gerberge de Tost (c1025-?)