 In March 68 , Gaius Julius Vindex , the governor of Gallia <unk> , rebelled against Nero 's tax policies . Lucius <unk> Rufus , the governor of Germania Superior , was ordered to put down Vindex 's rebellion . In an attempt to gain support from outside his own province , Vindex called upon Servius Sulpicius Galba , the governor of Hispania Tarraconensis , to join the rebellion and further , to declare himself emperor in opposition to Nero . 
