Throughout the early months of 69, Vespasian convened frequently with the Eastern generals. Gaius Licinius Mucianus was a notable ally. Governor of Syria and commander of three legions, Mucianus also held political connections to many of the most powerful Roman military commanders from Illyricum to Britannia by virtue of his service to the famous Neronian general Gnaeus Domitius Corbulo. In May 69, Mucianus formally implored Vespasian to challenge Vitellius. His appeal was followed by Vespasian’s official proclamation as Emperor in early July. Under instructions from the prefect Tiberius Alexander, the legions at Alexandria took an oath of loyalty to Vespasian on 1 July. They were swiftly followed by Vespasian’s Judaean legions on 3 July and thereafter by Mucianus’ Syrian legions on 15 July.
Nevertheless, Vitellius, the occupant of the throne, had Rome‘s best troops on his side – the veteran legions of Gaul and the Rhineland. But the feeling in Vespasian’s favour quickly gathered strength, and the armies of Moesia, Pannonia, and Illyricum soon declared for him, and made him the de facto master of half of the Roman world.
While Vespasian himself was in Egypt securing its grain supply, his troops entered Italy from the northeast under the leadership of Marcus Antonius Primus. They defeated Vitellius’ army (which had awaited him in Mevania) at Bedriacum, sacked Cremona and advanced on Rome. Vitellius hastily arranged a peace with Antonius, but the Emperor’s Praetorian Guard forced him to retain his seat. After furious fighting, Antonius’ army entered Rome. In the resulting confusion, the Capitol was destroyed by fire and Vespasian’s brother Sabinus was killed by a mob.
On receiving the tidings of his rival’s defeat and death at Alexandria, the new emperor at once forwarded supplies of urgently-needed grain to Rome, along with an edict assuring he would reverse the laws of Nero, especially those relating to treason. While in Egypt, he visited the Temple of Serapis where he reportedly experienced a vision. Later, he was confronted by two labourers, who were convinced that he possessed a divine power that could work miracles.
Vespasian was declared emperor by the Senate while he was in Egypt on 21 December 69; the Egyptians had declared him emperor in June. In the short-term, administration of the empire was given to Mucianus who was aided by Vespasian’s son, Domitian. Mucianus started off Vespasian’s rule with tax reform that was to restore the empire’s finances. After Vespasian arrived in Rome in mid-70, Mucianus continued to press Vespasian to collect as many taxes as possible.
Vespasian and Mucianus renewed old taxes and instituted new ones, increased the tribute of the provinces, and kept a watchful eye upon the treasury officials. The Latin proverb “Pecunia non-olet” (“Money does not stink”) may have been created when he had introduced a urine tax on public toilets.
Before Vespasian, this tax was imposed by Emperor Nero under the name of “vectigal urinae” in the 1st century AD. However the tax was removed after a while, it was re-enacted by Vespasian around 70 AD in order to fill the treasury.
Vespasian’s policy was not well received by his son. Writing about Vespasian in their history books, Dio Cassius and Suetonius mentioned “When [Vespasian’s] son Titus blamed him for even laying a tax upon urine, he applied to his nose a piece of the money he received in the first instalment, and asked him if it stunk. And he replying no, ‘And yet,’ said he, ‘it is derived from urine”. Since then, this phrase “Money does not stink” has been used to whitewash dubious or illegal origin of money.
In early 70 Vespasian was still in Egypt, the source of Rome’s grain supply, and had not yet left for Rome. According to Tacitus, his trip was delayed due to bad weather. Modern historians theorize that Vespasian had been and was continuing to consolidate support from the Egyptians before departing. Stories of a divine Vespasian healing people circulated in Egypt. During this period, protests erupted in Alexandria over his new tax policies and grain shipments were held up. Vespasian eventually restored order and grain shipments to Rome resumed.