King, with plea for help about rise of offspring, ruined city (7)
I believe the answer is:
knossos
'ruined city' is the definition.
(ancient Cretan city)
'king with plea for help about rise of offspring' is the wordplay.
'king with' becomes 'k' (I am not sure about this - if you are sure you should believe this answer much more).
'plea for help' becomes 'SOS' (Save Our Souls distress message).
'about' says to put letters next to each other.
'rise of' says the letters should be written backwards.
'offspring' becomes 'son' (male offspring).
'son' in reverse letter order is 'nos'.
'sos' put after 'nos' is 'nossos'.
'k'+'nossos'='KNOSSOS'
(Other definitions for knossos that I've seen before include "labyrinth" , "Ancient Cretan city" , "Minoan ruin in Crete" , "tourist attraction in Med" , "Minoan site on Crete" .)