Sovereign narrowed Zulu region only recently expanded, and that's controversial (4)

'only recently expanded and that's controversial' is the definition.
I know nothing about this answer so I can't tell whether this works.

'sovereign narrowed zulu region' is the wordplay.
I cannot quite understand how this works, but
'sovereign' could be 'l' (sovereign can mean pound and therefore L) and 'l' is present in the answer.
'zulu' could be 'z' (phonetic alphabet: alpha, bravo, charlie etc.) and 'z' is located in the answer.
'region' could be 'e' (E region is an example) and 'e' is present in the answer.
A single letter 'u' remains which might be clued in a way I don't see.
This may be the basis of the clue (or it may be nonsense).

Can you help me to learn more?