Il promo d'oro marked the wedding between Leopold I and what relation of Kind Philip IV?
Il pomo d'oro: Il pomo d'oro ("The Golden Apple") is an opera in a prologue and five acts by the Italian composer Antonio Cesti with a libretto by Francesco Sbarra (1611-1668). Il pomo d'oro:  Originally planned to mark the wedding of the Habsburg Holy Roman Emperor Leopold I and Margaret Theresa of Spain in 1666, the production was rescheduled to mark the Empress's 17th birthday in 1668. Margaret Theresa of Spain:  Daughter of King Philip IV of Spain and elder full-sister of Charles II, the last of the Spanish Habsburgs, she is the central figure in the famous "Las Meninas" by Diego Velázquez, and subject of many of his later paintings.
Daughter