Mogontiacum (Mainz) - Livius

On January 1, 69, the Roman garrison in Mainz began an uprising. From the article:

"...The operations were brought to a good end in the winter of 40/41, when Servius Sulpicius Galba (the future emperor) overcame the Chatti. After this success, troops could be reallocated, and when the emperor Claudius invaded Britain, the legions of Mainz were transferred. The new units were IIII Macedonica (which recruited its soldiers in Gallia Narbonensis) and Caligula's XXII Primigenia. They were still in Mainz in 69.

Troubles announced themselves in 68, when the emperor Nero committed suicide. He was succeeded by Galba, who distrusted the army of the Rhine. Unfortunately, he showed this a bit too much, and the legions revolted, proclaiming the general of the army of the Lower Rhine, Vitellius, emperor on 2 January 69. The garrison of Mainz supported him and took part in his march on Rome, where he was recognized by the Senate.

At that moment, however, the Batavians, a tribe living along the Lower Rhine, revolted. Because the garrisons were depleted, the rebels were able to capture Xanten and Cologne, force the remaining Roman units into surrender, and conquer parts of the Rhineland. The civil settlement of Mainz was taken by a rebel named Julius Tutor.

However, during the early spring of 70, the city liberated itself, and welcomed the Roman army commanded by Quintus Petillius Cerialis, a relative of Vitellius' enemy and successor Vespasian. Order was restored in the Rhineland. The new troops were the recently founded I Adiutrix (from Central Italy) and (again) XIV Gemina. The soldiers rebuilt the fortress out of stone and added an aqueduct with a length of nine kilometer. The source was near a village now called Finthen (from Latin fontes), and the remains of the arches can still be seen. At the same time, the first temple dedicated to Isis was erected..."