Following the murder of Domitian in 96, the "Adiutrix", along with the Danubian army, played an important role in Roman politics, forcing Nerva to adopt Trajan as his successor. When Trajan became emperor, he gave the legion the cognomen Pia Fidelis ("loyal and faithful") to acknowledge their support. Between 101 and 106, under the new emperor's command, I "Adiutrix", along with IV "Flavia Felix" and XIII "Gemina", conquered Dacia and occupied the newly formed province. Trajan also used his "Pia Fidelis" in the campaign against Parthia (115–117), but they were sent back to Pannonia by his successor emperor Hadrian, with base in Brigetio.