Following the Second Battle of Bedriacum (October 69), Vitellian resistance in northern Italy collapsed, persuading Gaul, Spain, and Britain to declare for Vespasian. Vespasian’s supporters—known as Flavians for Vespasian’s family name—then marched on Rome, capturing it in the first battle for the city since Sulla (in 82 BC). On 21 December the Senate proclaimed Vespasian the new emperor, marking the beginning of the Flavian dynasty.
Following the Second Battle of Bedriacum (October 69), the veteran soldier Valerius Paulinus led the garrison in Forum Julii (Fréjus), Gallia Narbonensis, to declare for Vespasian. Shortly afterwards Fabius Valens, one of the emperor Vitellius’ two principal commanders, left Pisa for Gaul to recruit more soldiers but was driven near Forum Julii by an adverse storm and captured by Paulinus. With the capture of Valens, Spain, Gaul, and Britain all declared for Vespasian (although the Rhine legions which had not joined the Batavian revolt remained loyal to Vitellius).in wikipedia
Queen Cartimandua of the Brigantes was a Roman client ruler in Britain, who had grown unpopular among her people both for her fidelity to the Romans and her rejection of her lower born husband Venutius for his armor-bearer Vellocatus. Encouraged by the Roman civil wars of 69 AD, Venutius led the Brigantes in revolt, compelling Cartimandua to call on the Romans for protection. Although they eventually managed to rescue her, the Romans, preoccupied by their own wars, were forced to accept Venutius’ usurpation for the time being.in wikipedia
In winter 69 AD the Roman fleet at Misenum (near Naples) revolted in favor of Vespasian, bringing the civil war to Campania. Meanwhile, the Danube legions advanced towards Rome through Umbria, persuading the Vitellian army guarding the Appenine pass at Narnia to defect. Realizing it was all over, Emperor Vitellius attempted to resign but was prevented from leaving the palace by his supporters. On 19 December Vespasian’s supporters (the Flavians) marched into Rome in three columns, defeating the Vitellians in a brutal two-day battle which destroyed much of the city and killed thousands. Captured, Vitellius was stabbed to death by the mob on the Gemonian stairs.in wikipedia