Old ruler makes more in Madrid (5)
I believe the answer is:
midas
'old ruler' is the definition.
'midas' can be an answer for 'ruler' (mythical king). I am not sure about the 'old' bit.
'more in madrid' is the wordplay.
'more' becomes 'm'.
'in madrid' becomes 'idas' (I can't explain this - if you can you should give a lot more credence to this answer).
'm'+'idas'='MIDAS'
'makes' is the link.
Can you help me to learn more?
(Other definitions for midas that I've seen before include "Legendary king whose touch turned anything to gold" , "my gift turned out a curse" , "Golden-touch king" , "Everything he touched turned to gold" , "King who turned what he touched to gold" .)