From Wikipedia, the free encyclopedia:

Total Annihilation: Kingdoms or TA:K is a medieval fantasy real time strategy game created by Clayton Kauzlaric and released by Cavedog Entertainment on June 25, 1999.

Story:

The story involves four sibling monarchs in their struggle to dominate the land of Darien : Elsin of Aramon, Kirenna of Veruna, Thirsha of Zhon and Lokken of Taros, following the disappearance of their father, Garacaius.
A more detailed story and world was presented in Total Annihilation: Kingdoms than was in Total Annihilation. The missions coincided with the storyline that was presented. In one example, a cutscene describes that the side of Aramon obtains the use of gunpowder. In that mission, the player plays the side of Aramon where using a gunpowder-based unit is critical towards the success of that mission. The game booklet and a detailed HTML atlas of Darien also added further background information to the storyline.


More information and game reviews:

Wikipedia
Mirror of Official Site
TA Universe
Gamespot review
IGN review