Complex sentence: Griffin was awarded the Pacem in Terris Award, named after a 1963 encyclical letter by Pope John XXIII that calls upon all people of good will to secure peace among all nations.
Split into simpler sentences: Griffin was awarded the Pacem in Terris Award. It was named after a 1963 encyclical letter by Pope John XXIII that calls upon all people of good will to secure peace among all nations.