The surface of Triannon after the war
- "We believe the Makers created the Chosen Realm in nine days; they believe it took ten."
"For that, you've been at war for almost a century?" - — Yarrick and Jonathan Archer, 2153
The Triannon War was a war between religious factions which broke out in the 2050s on the planet Triannon.
The reason for the war was the different religious view of the "Makers". While one faction believed the "Chosen Realm" was created in nine days the other faction believed the creation took ten days. The Triannons of both factions could be differentiated by the red and black tattoos on different sides of their faces.
In November of 2153 the leaders of the two factions, Pri'Nam D'Jamat and Ceris, saw the result of this war, the destruction of every city and building on the planet's surface. Captain Jonathan Archer of the Earth Starfleet vessel Enterprise (NX-01), told D'Jamat that the war was ended in March of 2153. (ENT episode: "Chosen Realm")