The Republic Age was to be the final Age planned for Age of Empires, following from the Iron Age. During development, Ensemble Studios deemed it unnecessary and merged it with the Iron Age.
It is mentioned in the game's code under the name Republic Age Not in use and remains inaccessible during gameplay.
| Ages in the Age of Empires series | |
|---|---|
 Age of Empires | |
 Stone Age ·  Tool Age ·  Bronze Age ·  Iron AgeCut: Prehistoric Age · Republic Age | |
 Age of Empires II | |
 Dark Age ·  Feudal Age ·  Castle Age ·  Imperial Age | |
 Age of Mythology | |
 Archaic Age ·  Classical Age ·  Heroic Age ·  Mythic Age ·  Titan Age (Removed) ·  Wonder Age | |
 Age of Empires III | |
 Exploration Age ·  Commerce Age ·  Fortress Age ·  Industrial Age ·  Imperial Age Revolution | |
 Age of Empires IV | |
 Dark Age ·  Feudal Age ·  Castle Age ·  Imperial Age | |
 Chronicles | |
 Archaic Age ·  Civic Age ·  Classical Age ·  Imperial Age |