His name shows that he had passed by adoption from the gens Mucia to the gens Licinia. He was sent by Claudius to Armenia with Gnaeus Domitius Corbulo. Under Nero he is recorded as suffect consul ca. 65.
At the time of the outbreak of the Jewish revolt in 66 AD, Mucianus was serving as governor of Syria, a post he still held during the Year of Four Emperors (69). He failed to put down the Jewish revolt and Vespasian was sent to replace him. After the death of Galba (69), Mucianus and Vespasian (who was at the time in Iudaea) both swore allegiance to Otho, but when the civil war broke out Mucianus persuaded Vespasian to take up arms against Vitellius, who had seized the imperial throne.
It was agreed that Vespasian should stay behind to settle affairs in the East, while Mucianus made his way through Asia Minor and Thrace to attack Vitellius. On the way he defeated a Dacian invasion of Moesia. He reached Rome the day after the death of Vitellius, and found Domitian, Vespasian's son, at the head of affairs, but until the arrival of Vespasian the real master of Rome was Mucianus who never wavered in his allegiance to Vespasian, whose favour he retained in spite of his arrogance. He is mentioned as suffect consul in 70 and 72. As no mention is made of Mucianus during the reigns of Titus or Domitian, he probably died during the reign of Vespasian.
He was a clever writer and historian. He made a collection of the speeches and letters of the Romans of the older republican period, probably including a corpus of proceedings of the senate (res gesta senatus), and was the author of a memoir, chiefly dealing with the natural history and geography of the East, which is often quoted by Pliny as source of miraculous occurrences.
- L. Brunn, Gaius Licinius Mucianus (Leipzig 1870).
- On Mucianus's memoir see George Williamson, "Mucianus and a Touch of the Miraculous: Pilgrimage and Tourism in Roman Asia Minor," in Jaś Elsner and Ian Rutherford, eds., Pilgrimage in Graeco-Roman and Early Christian Antiquity: Seeing the Gods. Oxford: Oxford University Press, 2005.
- Kleijn-Eijkelestam, G. de (2013). C. Licinius Mucianus, Vespasian’s Co-ruler in Rome. Mnemosyne. A Journal of Classical Studies, 66(3), 433–459.
- Kleijn-Eijkelestam, G. de (2009). C. Licinius Mucianus, Leader in time of Crisis. Historia, 58(3), 311–324.
- Kleijn-Eijkelestam, G. de The Water Supply of Ancient Rome: City Area, Water, and Population (Amsterdam 2001).
- This article incorporates text from a publication now in the public domain: Chisholm, Hugh, ed. (1911). Encyclopædia Britannica (11th ed.). Cambridge University Press.