Complex sentence: Cassius Dio, Roman History, 38.12.1 However, Clodius did not need to owe anything to Caesar to attack Cicero: he already bore a grudge against him because he had testified against him at this trial.
Split into simpler sentences: Cassius Dio, Roman History, 38.12.1 However, Clodius did not need to owe anything to Caesar to attack Cicero. He bore a grudge against Cicero because he had testified against him at this trial.