Information on horrendous king, shah or emperor (7,4)
I believe the answer is:
genghis khan
'emperor' is the definition.
(I know that Genghis Khan is a emperor)
'information on horrendous king shah' is the wordplay.
I cannot really see how this works, but
'information' could be 'gen' (gen can informally mean information) and 'gen' is found in the answer.
'king' could be 'k' (chess abbreviation) and 'k' is present in the answer.
This explanation may well be incorrect...
'or' acts as a link.
Can you help me to learn more?
(Other definitions for genghis khan that I've seen before include "Mongol conqueror, said to be right-wing" , "invader - with 16a" , "Empire-builder" , "Mongol emperor" , "Founder of the Mongol Empire, d. 1227" .)