Driven by the fiercest warriors in the galaxy, the great Klingon Empire has thrived for hundreds of years through the subjugation of feeble races. They value honor and strength above all else. The easiest way to make an enemy of a Klingon is to show weakness, or to suggest that they are weak. Offering to help a Klingon is an insult to their strength. They prefer death to dishonor, and would sooner self-destruct a ship than allow it to be towed home.

The Klingon-Federation relationship fluctuates between uneasy friendship and cold war with small skirmishes on both sides which often bring them to the brink of war. But, both sides generally find that their common enemies are more important than their mild disagreements.

Worf, son of Mogh was the first full Klingon to serve in Starfleet. His service paved the way for future Klingons to serve following the war with the Dominion.