Was the use of imperial nicknames in ancient Rome meant as an insult?

Question

A few Roman emperors are commonly known by nicknames. I'm thinking specifically of the Emperors Gaius (Caligula) and Antoninus (Caracalla.) These nicknames were never in official use, at least while they were alive. However, they seem to be by far the most commonly used names for said emperors today.

My question is whether the use of these nicknames after the deaths of these emperors is meant as an insult or a sign of contempt, or whether they were simply used for the sake of distinguishing one emperor from another of the same name (as with Antoninus, a name used by more than one emperor.) I ask because both of the listed emperors are widely regarded as two of the worst in Roman history. Caligula and Caracalla seemed to be used during those emperors' lives informally as agnomens, and both are based on pieces of clothing they wore. And Caligula, or "Little Boots", does seem kind of insulting or mocking as a nickname, referring as it does to the little soldier's boots that young Gaius wore while hanging around his father, the general Germanicus, while on campaign with the legions. (The implication of "Caracalla", translating as something like "Gallic cloak" supposedly based upon a style of cloak he liked to wear, is a little less clear to me.)

Answer 1

Caligula ("Little Boot," singular) was a nickname lovingly bestowed on the future emperor by his father, and was used by the soldiers as a term of endearment. It was never an insult.

I don't see how being nicknamed "Gallic Cloak" can be insulting. These two may not be as flattering as "Philip the Fair," "Louis the Sun King," or "Honest Abe," for that matter, but they do fall in the same category as, say, "Gentlemanly Johnny," the nickname General Burgoyne, who almost became Prime Minister of England once, was known by among friends and enemies alike.

Answer 2

The Romans were very into nicknames, probably because their naming system had so few personal names and because they were commonly inherited in a family, so it was not that uncommon for all the men in a family to have the same name! Nicknames were just part of life and were sometimes mocking, sometimes honoring, and probably most commonly just because.

Take the late republican general, Gnaeus Pompeius (Pompey). He adopted the nickname "Magnus" -- "the great" and was probably referred to as "Magnus" by equals in informal situations. (Note, BTW, that adopting your own nickname -- and choosing "Magnus" to boot -- took serious chutzpah. He must have been an intolerable young man.) His father, also a general and a consul, was Gnaeus Pompeius Strabo. "Strabo" means "cross-eyed" and may have been friendly and may have been mocking and probably was both. (Think how adolescent boys continually mock each other.) His grandfather was just Gnaeus Pompeius, as far as we know.

This is all pretty typical!

To judge whether or not a particular nickname is meant as a compliment or an insult or just what is usually beyond our ability at this remove. But in the particular case of Caligula, given that the story of it being given to him as a little boy and not as mockery comes from hostile sources, we can probably safely assume it is true.

Note that nicknames were used among equals. Few other than family and close friends would have addressed him as other than as Gaius Julius Caesar Augustus Germanicus.

Also, note that historians have tended to give important Romans distinguishing names. All three generations of Pompeys were probably called "Gnaeus Pompeius" in formal situations, but we tend to remember them as Pompey the Great and Pompey Strabo so we can keep them straight.

The Julio-Claudian emperors with their official names:

• Julius Caesar --> Gaius Julius Caesar
• Augustus --> Imperator Caesar Divi filius Augustus
• Tiberius --> Tiberius Caesar Divi Augusti fillies Augustus
• Caligula --> Gaius Julius Caesar Augustus Germanicus
• Claudius --> Tiberius Claudius Caesar Augustus Germanicus
• Nero --> Nero Claudius Caesar Augustus Germanicus

It's all about disambiguation!