In AD 19, in the Syrian City of Antioch a dastardly attempt by Tiberius' chief advisor, Sejanus to orchestrate the poisoning of Germanicus Julius Caesar was intercepted by the General's vigilant subordinates.
Germanicus wins out in SyriaHe had been sent to Asia to defeat the kingdoms of Cappadocia and Commagene and turn them into Roman provinces. But during a sightseeing trip to Egypt (not a regular province, but the personal property of the Emperor) he unwittingly usurped several imperial prerogatives. And he subsequently discovered that the governor of Syria, Gnaeus Calpurnius Piso, had canceled the provincial arrangements that he had made. Germanicus in turn ordered Piso's recall to Rome, although this action was beyond his authority.
The resulting conspiracy was quickly traced to Piso who later died while facing trial. This suspicious suicide prevented Germanicus from proving that Piso had acted under orders from Tiberius, but no matter because the General returned to Rome to proclaim himself Emperor.