Complex sentence: His appointment indicates that he, like his uncle John, future Bishop, was a client of James Butler, 2nd Duke of Ormond, as the Palatine was Ormond's personal feudal court, and he had the right to appoint the judges and other officials.
Split into simpler sentences: His appointment indicates that he, like his uncle John, future Bishop, was a client of James Butler, 2nd Duke of Ormond. The Palatine was Ormond's personal feudal court, and he had the right to appoint the judges and other officials.