[2] This incidental mention by Tacitus assumes significance when the historian introduces Varus in the Histories, where he tells us he provided damaging information about Corbulo to the emperor Nero in exchange for his promotion to primus pilus.
Although Vespasian, wishing to avoid bloodshed, had recommended that they wait on his further instructions, Primus, supported by Cornelius Fuscus, the procurator of Illyricum, advocated for immediate action.
[1] Once the five Balkan legions had reached him, Primus boldly marched upon the main Vitellian army at Cremona; Arrius Varus, his second-in-command, led the 4,000 cavalrymen.
By the time Gaius Licinius Mucianus, Vespasian's chief supporter, arrived in the capital city a few weeks later, both Varus and his superior Primus had secured themselves in positions of power.
[10] It helped that Primus was preoccupied with looting the imperial palace,[7] and Varus with rebuilding the Praetorian Guard, whose numbers had been depleted following the capture of Rome.
[8] Henriette Pavis d'Escurac notes that this was actually a demotion;[11] it is possible Varus' command of the Guard was, as Morgan suggests, self-appointed, and better a secure title than a tenuous one.
Morgan suggests, "Varus would fall from grace, but it looks as if he was brought down by score settling on the part of the daughter of Corbulo, the general he had traduced in Nero's reign.