Complex sentence: He graduated in jurisprudence in Palermo, where he lived until the Allied invasion of Sicily; he thenceforth lived in Rome, where he took part to the founding of Democrazia Cristiana.
Split into simpler sentences: He graduated in jurisprudence in Palermo, where he lived until the Allied invasion of Sicily. He moved to Rome, where he took part in the founding of Democrazia Cristiana.