Krios Prime

Krios Prime in 2367

Krios Prime in 2368

A Klingon settlement on Krios in 2367

Homeworld of the Kriosians, Krios or Krios Prime is a Klingon planet named after Krios, brother of Valt, who ruled the ancient Kriosian Empire together. The brothers became divided over the love for a woman named Garuth so eventually their empire fell. Krios even kidnapped Garuth from her homeworld Valt Minor and took her to Krios Prime, which would start a centuries long war between the two worlds. (TNG: "The Perfect Mate")

By the 22nd century, the Kriosians were under the rule of the Kriosian Sovereign Dynasty, a family known on hundreds of worlds. The royal guardsmen of the Dynasty were known as the Sovereign Guard. Their leader was known as the First Monarch, a post which Kaitaama would ascend to in 2153. (ENT: "Precious Cargo")

Sometime between the mid-22nd and mid-24th century, the Klingons would establish a colony on Krios, and subjugate the Kriosians under their rule. In 2367, the Federation was accused by the planet's governor, Vagh, of aiding the planet's rebels who hoped to free the planet from Klingon rule. However it was revealed that the Romulans were secretly aiding the rebels helped by a Klingon ambassador, Kell. (TNG: "The Mind's Eye")

In 2368, Krios and Valt Minor took their first steps towards peace as Kamala, the first female metamorph born on Krios since the mid-23rd century was married to Chancellor Alrik of Valt Minor. (TNG: "The Perfect Mate")

It is theorized that the Klingon "Krios" shown in "The Mind's Eye" is not the same as the "Krios Prime" we see in "Perfect Mate" and which is refered to in "Precious Cargo", due to the planet's changing appearance from blue to green and the total lack of any reference to the Klingons in the latter two episodes. However, as no information from those episodes suggests this theory, we assume it is the same planet.