After the civil war the legion joined the army of Augustus. It is believed to be identical to the Legio I that took part in the Hispania campaign against the Cantabri conducted for Augustus by Marcus Agrippa and was disgraced there. Inscriptions on coins from Hispania indicate that between 30 and 16 BC, some Legio I was stationed in Hispania Tarraconensis, where they would have fought in the war against the Cantabrians and Asturians. Dio Cassius (54.11.5) says that one legion was stripped of its title, Augusta, after suffering reverses in that campaign. The two references are believed to be to the same legion, accounting for its early missing title and emblem. While in Spain they helped build the colonia Acci.