Complex sentence: Henry II succeeded in persuading Pope Benedict VIII to include the Filioque to the Nicene Creed, stating that the Holy Spirit emanated from both God the Father and God the Son.
Split into simpler sentences: Henry II succeeded in persuading Pope Benedict VIII to include the word "Filioque" in the Nicene Creed. This word provided that the Holy Spirit emanated from both God the Father and God the Son.