Complex sentence: Immediately a search party is sent out, Prince Rhun in command; however, King Rhuddlum knows that his son is unfit for command and tells Taran that while Rhun is in charge in name, Taran is in charge in fact.
Split into simpler sentences: Immediately a search party is sent out, Prince Rhun in command. However, King Rhuddlum knows that his son is unfit for command and tells Taran that while Rhun is in charge in name, Taran is in charge in fact.