Emperor in cape others in Rome drag back inside (8)
I believe the answer is:
caligula
'emperor' is the definition.
(Roman emperor)
'cape others in rome drag back inside' is the wordplay.
'cape' becomes 'c' (abbreviation used on maps).
'others in rome' becomes 'alia' ('others' in Latin).
'drag' becomes 'lug' (I've seen this in other clues).
'back' says the letters should be written in reverse.
'inside' means one lot of letters goes inside another.
'lug' backwards is 'gul'.
'alia' enclosing 'gul' is 'aligula'.
'c'+'aligula'='CALIGULA'
'in' acts as a link.
(Other definitions for caligula that I've seen before include "Roman emperor, notorious for his cruelty" , "Third Roman emperor" , "Successor to Tiberius" , "imperial figure" , "Emperor after Tiberius" .)