The most common and most likely answer to this crossword clue is the 8 letter word CALIGULA
I've seen this crossword clue in The Daily Telegraph
C
A
L
I
G
U
L
A
More clues leading to the result CALIGULA
- Did he come after Julius riding a noble steed?
- Emperor in cape others in Rome drag back inside
- Single weapon briefly in contact with a Roman emperor
- Roman emperor, not altogether calm, getting one Gaul destroyed
- A lilac jug missing top represented emperor
- 40% state “short seabird and a crazy Roman”
- Unionist blocking representation of a Gallic imperial figure
- Emperor about to admit fighter to haul back
- Emperor, a guy I call unbalanced, not unknown
- Family almost broken by contrary leader in unscrupulous monster, Roman emperor
Buddy explains!
The straight part
We know that "emperor" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case emperor = caligula.The cryptic/wordplay part
In cryptic crossword there's often an wordplay/cryptic part as well.This part involves a more complex hint, such as an anagram, homophone, hidden word, etc.
Sadly, We don't have an explanation for this specific crossword clue yet.