IPA: /ˈɛmpəri/
KK: /ˈɛmpəri/
Complete control or authority over a territory or domain.
The king ruled with an empery that extended far beyond his borders.
Empery originates from Middle English 'emperie', derived from Old French 'empire', which in turn comes from Latin 'imperium' (meaning command or authority). The word refers to the state of having supreme authority or dominion.
Think of 'imperium' meaning command or authority to remember that 'empery' refers to the state of having supreme authority.