fiefdom
Pronunciation:
/ˈfiːf.dəm/noun
Definitions
The estate controlled by a feudal lord; a fief.
Example: The duke's fiefdom had been greatly expanded as a reward for his dutiful military service on behalf of the king.
(by extension) Any organization in the control of a dominant individual.
Example: Most of our company's computers are standardized, but the IT director allows the employees in his own little fiefdom to specify their own machines.