Original: John I, as Saxony's incumbent king, was subordinate and owed allegiance to the Emperor, although he, like the other German princes, retained some of the prerogatives of a sovereign ruler, including the ability to enter into diplomatic relations with other states.
Simplified: John I, as Saxony's king, was below the Emperor, although he, like the other German princes, kept some of the rights of a sovereign ruler, including sending ambassadors  other states.