Complex sentence: A secondary reason for Caesar's immediate want for another consulship was delaying the inevitable senatorial prosecutions awaiting him upon retirement as governor of Illyricum and Gaul; said potential prosecutions were based upon alleged irregularities occurred in his consulship, and war crimes committed in his Gallic campaigns.
Split into simpler sentences: A secondary reason for Caesar's immediate want for another consulship was delaying the inevitable senatorial prosecutions awaiting him upon retirement as governor of Illyricum and Gaul. These potential prosecutions were based upon alleged irregularities occurred in his consulship and war crimes committed in his Gallic campaigns.