Federation-Klingon War of 2256-2257

"What are you looking for? More territory? Conditional surrender? Your people won't even make demands, why? How does this war end?" "It doesn't. Klingons have tasted your blood. Conquer us...or we will never relent."

- Katrina Cornwell and L'Rell, 2257

The Federation-Klingon War of 2256 was a conflict fought between the United Federation of Planets and the Klingon Empire

Background
Following the formation of the Federation in 2161, the Klingons saw them as an opponent by the 2220s and were close to going to war. However, two powers did not engage in direct contact with each other for next century. The first time the Federation and Klingon Empire fought at the Donatu V in 2245. However, it was a stalemate and inconclusive battle. Despite that, Klingons were able to launch a raid on Doctari Alpha. In all these encounters, no one in the Federation had seen a Klingon since Captain Jonathan Archer's mission to Qo'noS and Empire in 2250s.