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 cannot judge whether it can be defined by this definition.

'sovereign narrowed zulu region' is the wordplay.
I cannot quite see how this works, but
'sovereign' could be 'l' (sovereign can mean pound and therefore L) and 'l' is located in the answer.
'zulu' could be 'z' (phonetic alphabet: alpha, bravo, charlie etc.) and 'z' is found 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 understand.
This may be the basis of the clue (or it may be nonsense).

Can you help me to learn more?