It was an uprising against the Roman Empire started by the Batavi, a small but militarily powerful Germanic tribe that inhabited Batavia, on the delta of the river Rhine.

Following peace talks, the Batavi submitted again to Roman rule, but were forced to accept humiliating terms and a legion stationed permanently on their territory, at Noviomagus (modern day Nijmegen, The Netherlands).

The Batavi were a sub-tribe of the Germanic Chatti tribal group who had migrated to the region between the Old Rhine and Waal rivers (still today called the Betuwe after them) in what became the Roman province of Germania Inferior (S Netherlands/Nordrhein).

Their land, in spite of potentially fertile alluvial deposits, was largely uncultivable, consisting mainly of Rhine delta swamps.

In return for the unusual privilege of exemption from tributum (direct taxes on land and heads that most peregrini were subject to), they supplied a disproportionate number of recruits to the Julio-Claudian auxilia, particularly in the cavalry: one ala and eight cohortes.

They also provided most of the emperor Augustus' elite regiment of Germanic bodyguards (Germani corpore custodes), which continued in existence until AD 68.

[3] In Roman service, they had perfected a unique technique for swimming across rivers wearing full armour and weapons.

After the Batavi regiments were withdrawn from Britain in 66, Civilis and his brother (also a prefect) were arrested by the governor of Germania Inferior on false accusations of treason.

The governor ordered the brother's execution, and sent Civilis to Rome in chains for judgement by the Roman emperor Nero.

(The difference in treatment indicates that the brother was still a peregrinus, i.e. a non-citizen subject of the empire, while Civilis, as his name implies, had been accorded Roman citizenship, which entitled him to have his case heard by the emperor in person).

While Civilis was in prison awaiting trial, Nero was overthrown in AD 68 by an army led into Italy by the governor of Hispania Tarraconensis, the veteran general Galba.

Nero committed suicide, ending the rule of the Julio-Claudian dynasty, founded a century earlier by Augustus.

[8] At the same time, relations collapsed between the eight Batavi cohorts and their parent-legion XIV Gemina, to which they had been attached since the invasion of Britain 25 years earlier.

The descendants of Augustus had enjoyed the automatic and fervent loyalty of ordinary legionaries in the frontier armies, but Galba possessed no such legitimacy in their eyes.

The first action was to set up a decoy and Civilis induced a rebellion outside of Batavia and fragment the Northern Roman army.

Let Syria, Asia Minor, and the East, habituated as it is to despotism, submit to slavery... Freedom is a gift bestowed by nature even on the dumb animals.

The inducements used by Civilis to instigate rebellion are not known, but the Cananefates, led by their chief Brinno, attacked several Roman forts, including Traiectum (Utrecht).

Accompanying them were three auxiliary units, including a Batavian cavalry squadron, commanded by Claudius Labeo, a known enemy of Civilis.

The Roman army was beaten and the legions forced to retreat to their base camp of Castra Vetera [de] (modern Xanten).

Even Vespasian, who was fighting Vitellius for the imperial throne, saluted the rebellion that kept his enemy from calling the Rhine legions to Italy.

Moreover, the eight Batavian auxiliary units of Vitellius' army were on their way home and could be easily persuaded to join the rebellion for an independent Batavia.

In September 69, Civilis initiated the siege of Castra Vetera, the camp of the 5,000 legionaries of V Alaudae and XV Primigenia.

The camp was very modern, filled with supplies and well-defended, with walls of mud, brick, and wood, towers, and a double ditch.

Vespasian was winning the war and Civilis was helping him to become emperor by preventing at least the two legions besieged in Castra Vetera, loyal to Vitellius, from coming to his rescue.

Knowing that the Romans would come to Castra Vetera, Civilis abandoned the siege and threatened to attack Moguntiacum.

He nominated Quintus Petillius Cerialis, a close relative and experienced general, as commander of the avenging force.

The legions VIII Augusta, XI Claudia, XIII Gemina, XXI Rapax, and the recently levied II Adiutrix were immediately sent to Germania.

From his homeland of Batavia, Civilis tried for some time to attack the Roman army in a series of raids by land and, with the help of his fleet, in the rivers Waal and Rhine.