Legio XXI Rapax: one of the Roman legions. The name means "predator".
This legion was probably founded after 31 BCE by the emperor Augustus, who may have integrated older units into this new legion and added new recruits from northern Italy.
Its first assignment may have been in Hispania Tarraconensis, where it took part in Augustus' campaigns against the Cantabrians, which lasted from 25-13 BCE. However, the legion's stay in Hispania is nothing but a hypothesis. We have more certainty about its stay in Raetia, which was annexed in 15 by Augustus' son-in-law Tiberius (the future emperor). Its base was probably at Regina Castra, modern Regensburg.
In 6 CE, Tiberius was to lead at least eight legions (VIII Augusta from Pannonia, XV Apollinaris and XX Valeria Victrix from Illyricum, XXI Rapax from Raetia, XIII Gemina, XIV Gemina and XVI Gallica from Germania Superior and an unknown unit) against king Maroboduus of the Marcomanni in Czechia. At the same time, I Germanica, V Alaudae, XVII, XVIII and XIX were to move against Maroboduus along the Elbe. It was to be the most grandiose operation that was ever conducted by a Roman army, but a rebellion in Pannonia obstructed its execution. XXIRapax was involved in its suppression.
After the disaster of Varus in the Teutoburg Forest (September 9 CE), where the legions XVII, XVIII and XIX were destroyed, the legion was redeployed in the province of Germania Inferior. It shared its base at Xanten with V Alaudae, keeping an eye on the nearby tribes of the Cugerni and Batavians, and guarding the confluence of the Rhine and Lippe. Both units took part in the Germanic campaigns of Germanicus in the first years of the reign of Tiberius (14-16; described here).
In 21, a mixed subunit of XXI Rapax and XX Valeria Victrix, commanded by an officer from I Germanica, was sent out to suppress the rebellion of the Turoni in Gaul, who had revolted against the heavy Roman taxation under a nobleman named Julius Sacrovir and Julius Florus. Almost twenty years later, the Twenty-first was employed during the Germanic war of Caligula. The details, however, are not fully understood.
After Claudius' invasion of Britain in 43, XXI Rapax was redeployed in Germania Superior, which was now undergarrisoned. After a possible (but not proved) brief stay at Strasbourg, our unit was transferred to Vindonissa (modern Windisch in Switzerland), where it succeeded XIII Gemina. Here, it defended the passes across the Alps against a possible Germanic invasion of Italy.
In 47, the soldiers rebuilt the fortress, which had been constructed out of wood, from natural stone and bricks. At Ruperswyl, they built kilns, where tiles and pottery were produced - not only for Windisch, but also for other military settlements in this area.
In the civil war after the suicide of the emperor Nero (June 68), the Twenty-first sided with Vitellius, the commander of the army of Germania Inferior. In fact, the twenty-first legion was the most important element in the army of Vitellius' general Caecina. It crossed the Alps during the winter, defeated the army of Otho at Cremona, marched on Rome and was victorious (69). However, before the year was out, Vitellius' army had been defeated by the troops of another pretender, Vespasian, who was to reign until 79.
It took several months before the new emperor could send a strong army to recover the Rhineland, which had been overrun by rebellious Batavians. The expeditionary force was commanded by Vespasian's relative Quintus Petillius Cerialis, and XXI Rapax was one of its units. It fought at Trier and must have been present during the battle of Xanten.
After the reconquest, the Twenty-first was replaced at Windisch by XI Claudia and initially garrisoned at Bonn in Germania Inferior, but sent back to Superior in 83 when Vespasian's son, the emperor Domitian, launched a war against the Chatti in Baden-Württemberg. Bonn was occupied by the recently founded I Minervia.
From now on, Mainz was the legionary base of XXI Rapax and XIV Gemina. When in 89 the governor of Germania Superior, Lucius Antonius Saturninus, revolted against the lawful emperor Domitian, the two legions supported him. However, the insurrection was suppressed by the legions of Germania Inferior and the two rebellious units were immediately separated - the Twenty-first being sent to Pannonia, where war against the tribes of the Middle Danube - the Suebians and Iazyges - was imminent. Here, the Twenty-first was destroyed in 92 by the Sarmatians.
The legionary symbol of XXI Rapax was the Capricorn, which was often used by units that had been founded by the emperor Augustus.
- F. Berard, "La légion XXIe Rapax", in: Yann Le Bohec, Les légions de Rome sous le Haut-Empire (2000 Lyon) 49-67
- L. Rossi, "Legio XXI Rapax... atque Infidelis?", in: Yann Le Bohec, Les légions de Rome sous le Haut-Empire (2000 Lyon) 491-498