King upsetting earls after church (7)
I believe the answer is:
charles
'king' is the definition.
(I've seen this before)
'upsetting earls after church' is the wordplay.
'upsetting' is an anagram indicator.
'after' means one lot of letters go next to another.
'church' becomes 'ch' (common abbreviation).
'earls' anagrammed gives 'arles'.
'arles' after 'ch' is 'CHARLES'.
(Other definitions for charles that I've seen before include "27 [PRINCE]" , "Possible name" , "- Kingsley (The Water Babies)" , "Man's name" , "[LAWMAKER]?" .)