Examples Envoy Extraordinary in German examples

How do I translate Envoy Extraordinary into German?

Movie subtitles

Knight of the Holy Roman Empire, Envoy Extraordinary. from His Majesty Philip, King of Spain, Aragon and Castile.

Ritter des Heiligen Römischen Reiches, Sonderbote Seiner Majestät Philip, König von Spanien, Aragon und Kastilien.