Complex sentence: The Roman Inquisition began in 1542 when Pope Paul III established the Holy Office as the final court of appeal in trials of heresy and served as an important part of the Counter-Reformation.
Split into simpler sentences: The Roman Inquisition began in 1542 when Pope Paul III established the Holy Office as the final court of appeal in trials of heresy. It served as an important part of the Counter-Reformation.