On the death of Amyntas in 25 BC, Deiotarus' successor, the Galatian kingdom was absorbed into the Roman Empire. A papyrus recovered from Egypt, dated 8 BC, mentions two soldiers of the legion. Between these two dates, the Galatian army was incorporated as a legion into the Roman army. M.H.D. Parker argues that the date of its incorporation could be narrowed further as between 16 BC and 8 BC; since Caesar Augustus had already 21 legions, the legion received the number XXII.