### Clue: Thessalian ruler, jealous when roused, without justice (6)
### Answer: AEOLUS 
 ### Explanation: Definition: Thessalian ruler
JEALOUS* less J. There are several mythological characters called Aeolus – the ruler of Thessaly is (I think) this one – not the keeper of the winds who gave his name to the Aeolian mode and harp