What is XXX's brothers name?
Elisabeth of Nassau-Dillenburg
Countess Elisabeth of Nassau-Dillenburg (born 25 September 1542 in Dillenburg -- died: 18 November 1603 in Dillenburg) was a daughter of William I, Count of Nassau-Dillenburg and Juliana of Stolberg and was one of the sisters of William the Silent.
William the Silent