Legio XXI Rapax, the predator, was a Roman legion levied in 31 BC by Augustus, probably from men previously enlisted in other legions. The XXI Rapax was destroyed in 92 by the Dacians and Sarmatians. The symbol of the legion was a capricorn[1].
The legio has occupied Vindonissa from 46 to 69 with two auxiliary cohorts, first the III Hispanorum and VI Raetorum, and later the VII Raetorum equitata and the XXVI voluntariorum civium Romanorum.
Along with the rest of the German border army, the XXI Rapax supported its commander, Vitellius, in the Year of the Four Emperors (69) and marched to besiege Rome. Vitellius was, however, defeated by Vespasian before the end of the year.
In 70, the legion was part of the army sent to deal with the Batavian rebellion and relieve the four legions imprisoned by Civilis. After that they were sent to Germania Superior, where they shared the castrum (camp) of Moguntiacum (modern day Mainz) with XIV Gemina.
In 89, the legions in Moguntiacum supported their commander, Lucius Antonius Saturninus, in his revolt against emperor Domitian. After the end of this harmless insurrection, the legions were separated and XXI Rapax sent to Pannonia. The legio was sent in Moesia Inferior where they were destroyed at Tropaeum Traiani during the revolt of the Sarmatians in 92.
