Summary The article examines unofficial imperial nicknames, sobriquets and appellatives, from Octavian Augustus to Julian the Apostate, in the light of traditions of Roman political humour, and argues that in the political field during the Principate there were two co-existing competing modes of emperors’ naming: along with an official one, politically loyal, formalised and institutionally legitimised, there existed another – unofficial, sometimes oppositional and even hostile towards individual emperors, frequently licentious, humorously coloured and, in this regard, deeply rooted in Roman (...) Republican traditions of political humour. Many of the known imperial nicknames and appellatives belong to a specific kind of folklore and express popular public opinion. They survived for us because of ancient authors’ interest in using such material for their literary and ideological intentions, particularly to express better the individual characteristics of the historical personages. But, for the very same purposes, Greek and Roman writers could invent some names and sobriquets, following special rhetorical and moralising principles, or mere love of ridicule. All in all, most imperial nicknames, both authentic and made-up, reveal a rather good quality of humour and mockery constructed by expressive linguistic devices and various rhetorical tropes. An apt derisive nickname marked anti-values, mocked the ruler’s badness and could vilify his reputation to the extreme, stigmatise his personality, or else become a widely-used quasi-cognomen. Many nicknames and appellatives were of ephemeral, ad hoc nature, their sense and effect largely dependent on the particular context; but, taken as a whole, they demonstrate the possible scope of and common trends in naming practice. The political system of the Principate and its very atmosphere of hypocrisy did promote double meaning and double thinking reflected in the double system of the rulers’ nomenclature. Imperial nicknames were a counter-hegemonic transcript and a weapon in the struggle for symbolic capital. All the efforts which many emperors took to control their nomina were ultimately powerless against the strength of the inevitable humorous counter-naming by the ruled. (shrink)