[3][4] The third theory attributes its recruitment to Gaius Vibius Pansa Caetronianus, a partisan of Caesar, who died in the Battle of Forum Gallorum against Mark Antony in 43 BC.
[1] 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.
Most likely, the title Germanica was granted for service in Drusus' subsequent punitive and exploratory campaigns against the Germanic tribes.
[1] After the defeat of Varus, Augustus' adoptive son Tiberius (brother of Drusus) assumed command of the army on the Rhine, which was reinforced to eight legions.
When Tiberius returned to Italy in 13 AD, Augustus appointed Drusus' son, Germanicus, commander of the eight legions on the Rhine.
Subsequently Junius Blaesus, commander of three legions in summer camp in Pannonia, gave the men a holiday.
The men as he spoke began raise a dais of earth around him and brought the standards and that attracted the attention of the Praetor, Blaesus.
Arresting their commander, Aufidienus Rufus, they forced him to march at the head of the return column carrying heavy baggage and asking him all the while how he liked it.
Attempting to quell it, Blaesus had loyal troops throw the rioters in the guardhouse, but they were set free, the tribunes were ejected from camp, and a harsh centurion murdered.
The soldiers were on the point of killing each other when Tiberius' own son, Drusus Julius Caesar arrived in camp with some troops, sealed the gates and proceeded to investigate and settle the mutiny in tribunal.
The XXI Rapax, V Alaudae, I Germanica and XX Valeria Victrix of the army of Germania Inferior heard of the mutiny at their summer camp among the Ubii.
Aroused by new recruits from the city of Rome, the men attacked the centurions by surprise, beating many to death and throwing the bodies into the Rhine.
Hearing of the mutiny, Germanicus left his tax-collecting duties in Gaul and hastened to the camp with a small retinue.
In realization of the common danger the men settled for immunity, double pay (which Germanicus gladly paid from his own funds on the spot) and an enlistment of sixteen years.
I Germanica and the XX Valeria Victrix retired to Cologne, while Germanicus went to seek senatorial confirmation and approval by Tiberius.
Upset, Germanicus tried to send his pregnant wife and young son off to safety, but the soldiers heard them weeping and came out to detain them.
Aroused, Germanicus delivered one of the great orations in history, upholding the tradition of his family's ability in that area, saying, for example: Moved and stung to the quick, the soldiers settled the mutiny on the spot by general court martial conducted by the tribunes.
[1] Although the Legio I Germanica, led by Herennius Gallus, XVI Gallica and a legion from Germania Superior, XXII Primigenia, attempted to reinforce them, they were made to surrender in March 70.
[6][11][12] It would be several months before emperor Vespasian could muster a strong force, led by Quintus Petillius Cerialis, to restore control over the Rhineland and subdue the Batavian revolt.