Despite his difficult relationship with the Senate, Tiberius' first years were generally good. He stayed true to Augustus’s plans for the succession and favoured his adopted son and nephew Germanicus over his natural son, Drusus, as did the Roman populace. On Tiberius' request, Germanicus was granted proconsular power and assumed command in the prime military zone of Germania, where he suppressed the mutiny there and led the formerly restless legions on campaigns against Germanic tribes from AD 14 to 16. Germanicus died in Syria in AD 19 and, on his deathbed, accused the governor of Syria, Gnaeus Calpurnius Piso, of murdering him at Tiberius’s orders. With Germanicus dead, Tiberius began elevating his own son Drusus to replace him as the Imperial successor. By this time Tiberius had left more of the day-to-day running of the Empire to Lucius Aelius Sejanus.