Many appeared before Arthur's court (7)
I believe the answer is:
camelot
'arthur's court' is the definition.
(I've seen this before)
'many appeared before' is the wordplay.
'many' becomes 'lot' (a lot of something).
'appeared' becomes 'came' (I've seen this before).
'before' means one lot of letters go next to another.
'lot' after 'came' is 'CAMELOT'.
(Other definitions for camelot that I've seen before include "King Arthur's kingdom - or JFK's" , "Legendary Arthurian kingdom" , "King Arthur's court - or JFK's" , "mythical place" , "Arthur's or Kennedy's court?" .)