What is the name of the elder brother emperor that signed the Truce of Ratisbon?
Truce of Ratisbon:  The Truce was signed on 15 August 1684 at the Dominican convent at Ratisbon in Bavaria between Louis XIV of France on the one side, and the Holy Roman Emperor, Leopold I, and the Spanish King, Charles II, on the other. Leopold I, Holy Roman Emperor:  The second son of Ferdinand III, Holy Roman Emperor, by his first wife, Maria Anna of Spain, Leopold became heir apparent in 1654 by the death of his elder brother Ferdinand IV.
Ferdinand IV