Two different queens support a future emperor, perhaps (11)
I believe the answer is:
caterpillar
'a future emperor perhaps' is the definition.
I can't judge whether this defines the answer.
'two different queens support' is the wordplay.
'two different queens' becomes 'cater' (I am not sure about this - if you are sure you should give a lot more credence to this answer).
'support' becomes 'pillar' (pillar is a kind of support).
'cater'+'pillar'='CATERPILLAR'
Can you help me to learn more?
(Other definitions for caterpillar that I've seen before include "Butterfly/moth larva" , "potential beauty?" , "Tiny creature" , "Lepidopteran larva" , "sort of grub" .)