Party of French monarch includes a minstrel (9)
I believe the answer is:
balladeer
'minstrel' is the definition.
(thesaurus)
'party of french monarch includes a' is the wordplay.
'party' becomes 'ball' (ball is a kind of party**).
'of french' becomes 'de'.
'monarch' becomes 'er' (abbreviation for Elizabeth Regina).
'includes' indicates putting letters inside.
'ball'+'de'+'er'='balldeer'
'balldeer' enclosing 'a' is 'BALLADEER'.
(Other definitions for balladeer that I've seen before include "One making a song" , "Minstrel" , "pop singer" , "One sings" .)