Once you enter Age IV you will be able to use your races unique special building to train high powered 'Elite' units that are exclusive to each civilization. These units are only accessible upon reaching Age IV and will cost considerably more resources to develop.
The Elite units and special buildings are:
- The Mongols
Special Building: Chamber of Erlik
Elite Units: Naffatun, Mangudai & Elite Mangudai
- The Turks
Special Building: Ertuğrul's Edifice
Elite Units: Janissary, Qapukulu & Elite Qapukulu
- The Kingdom of Jerusalem
Special Building: Templar Society
Elite Unit: Templar Crossbowmen, Knights Templar & Elite Knights Templar
- The Byzantine Empire
Special Building: Kataphraktoi Fort
Elite Unit: Greek Firethrower, Cataphract & Elite Cataphract