What type of leaden does Gertrude of Brunswick and Henry V, Holy Roman Emperor have in common?
Gertrude of Brunswick Gertrud of Brunswick (German: "Gertrud von Braunschweig" ;  1060 – 9 December 1117), was Countess of Katlenburg by marriage to Dietrich II, Count of Katlenburg, Margravine of Frisia by marriage to Henry, Margrave of Frisia, and Margravine of Meissen by marriage to margrave Henry I. She served as regent of the County of Katlenburg during the minority of her son Dietrich III of Katlenburg, and as regent of the County of Northeim during the minority of her son Otto III of Northeim. She was also one of the leaders of the insurrections against Emperor Henry IV and his son Henry V.
Henry I, Margrave of Austria Henry I (German: "Heinrich" , died 23 June 1018), known as Henry the Strong (German: "Heinrich der Starke" ), was the Margrave of Austria from 994 to his death in 1018. He was a member of the House of Babenberg.