Thousand-year empire: the long-lasting or "eternal" rule of a given society.
1) Christ's dominion on Earth prior to the Day of Judgment according to the Gospel of John. Prior to the Last Judgment, ►Jesus Christ, along with the resurrected righteous, will establish a thousand-year empire of peace and joy on Earth. It will end with the Apocalypse, the resurrection of the remaining dead, and their assignment to either heaven or damnation in hell in the Last Judgment.
2) Actually existing empires with a life-span of 1000 or more years were:
(3032 B.C. to 332 B.C.)
The only thousand-year empire that described itself as such lasted only 12 years.