Stronghold of a boy king? (6)
I believe the answer is:
castle
This could be a double definition.
'stronghold' is the first definition.
(I know that castle is a type of citadel)
'a boy king?' is the second definition.
'castle' can be an answer for 'king?' (thesaurus). I'm not sure about the 'a boy' bit.
'of' acts as a link.
Can you help me to learn more?
(Other definitions for castle that I've seen before include "E.g. Harlech, Beaumaris, Windsor" , "Dover, perhaps" , "Stronghold - chessman" , "Fort" , "Move rook and king in the same turn" .)