kinglet

noun4

1. •
   A young or little king.
2. •
   Any of several birds of the family Regulidae.
3. •
   (disapproving) A petty king; a king ruling over a small or unimportant territory.

   • Caesar termeth all the Lords, which in his time had justice in France, to be Kinglets [tr. reguli], or pettie Kings. — 1603
4. •
   A prince.