When Commodus became Caesar, he shared imperial authority equally with Marcus Aurelius at first then increasingly played a larger role in Rome as a senior partner alongside his father. While Aurelius focused on the German campaign as well as military discipline Commodus was tasked with dealing with civil affairs which were not within his father's sphere as emperor (like building works, games and ceremonies) until 176 he also had authority when it came to appointing men to the post of tribune.