Krenim The Krenim were a technologically - advanced humanoid species from the Delta Quadrant , first encountered by the Federation starship in 2374 . The Krenim government was called the Krenim Imperium . At 98 % restoration , the Krenim Imperium of 2374 was composed of over two hundred star systems , nine hundred planets , and thousands of warp - capable vessels spread out over five thousand parsec s . ( ) " " In the Year of Hell , " Voyager " traversed Krenim space beginning on stardate 50973 , enduring constant Krenim attacks . A large number of the crew was killed , including Captain Kathryn Janeway , B ' Elanna Torres , and Joseph Carey . During one of the Krenim attacks , Kes was exposed to chroniton radiation which leaked through the hull from a chroniton torpedo fragment . Much later in 2379 , The Doctor ' s attempt to extend her short Ocampa n life span using a bio - temporal chamber activated the dormant chroniton s inside her body , causing her to travel randomly backwards in time to various points in her own life . The Doctor of 2373 was able to purge the chronitons using anti - chroniton s , synchronizing Kes to the year 2373 . While she was in 2373 , Kes warned Janeway of the Krenim danger . " ( ) According to the Krenim officer known as Annorax , their greatest adversary was a race known as the Rilnar . Unbeknownst to the Krenim , however , the Rilnar had introduced a crucial antibody into the Krenim genome which prevented certain diseases from affecting the Krenim . " In at least one alternate timeline , Annorax wiped out the Rilnar civilization without realizing the existence of the antibody and an epidemic swept across the Krenim homeworld , killing fifty million people in the first year alone . " " In a number of separate alternate timelines in 2374 , " Voyager " attempted to enter Krenim territory . Initially , they encountered only a small , poorly armed Krenim ship . In this timeline , the region was dominated by the Zahl , who had ended the Krenim domination of the region a generation previously . This timeline was changed when the Krenim weapon ship erased the Zahl civilization , removing the entire species from history . In this new timeline , the Krenim Imperium was near the height of its power , and launched a series of devastating attacks on " Voyager " much like the " year of hell " of Kes ' s possible future . " Eventually , " Voyager " developed temporal shield s to defend against the Krenim , which in turn perturbed the temporal calculations made by the weapon ship . Thus , the elimination of the Garenor species , intended to further restore the Imperium , instead created a third alternate timeline where the Krenim regressed to a pre - warp society . The temporal shields protected " Voyager " from the changes to the timeline , and its crew was able to see the changes the Krenim had made . ( ) Eventually " Voyager " created an alliance with the Mawasi and the Nihydron in order to attack the weapon ship . The damage they dealt to the weapon ship caused it to erase itself from the timeline , undoing all of the damage it had done . In this restored timeline , " Voyager " encountered a Krenim warship in 2374 . Its commandant warned Captain Janeway that the region of space they were passing through was in dispute and that they should avoid it if possible . He wished them good journey and the two ships went their separate ways . ( ) Members of this species had been assimilated by the Borg by 2375 . ( ) Appendices . Apocrypha . In the computer game " Star Trek Online " , the Krenim have been specifically targeted by the Vaadwaur ( under the direction of the Iconians ) and nearly driven to extinction , likely due to their expertise in temporal mechanics . Though the race appears to have been all but destroyed , a lone Krenim colony - ironically , the colony on Kyana Prime - was able to use Annorax ' s research to hide their entire planet from the Vaadwaur and their Iconian masters . The player character and Captain Nog discover the colony and convince them that the Delta Alliance ( the Federation , the Klingon Empire , the Romulan Republic , and several Delta Quadrant species ) mean them no harm . The Krenim band together with the Delta Alliance to construct their own version of Annorax ' s temporal weapon ship to combat the Iconians . A rogue band of Krenim , led by the scientist Noye , become major antagonists of the " Agents of Yesterday " storyline as they form the " Temporal Liberation Front " , consisting of the Sphere - Builder s , the Vorgon s , and the Na ' kuhl , in opposition to the Temporal Accord . In the novel " A Pocket Full of Lies " , following the events of the Year of Hell , the Krenim of the new timeline have established a variation of the Department of Temporal Investigations known as the Krenim Temporal Defense Agency . In contrast to the DTI , the Agency ' s goal appeared to be to use time travel to subtly ensure Krenim supremacy in the present timeline , rather than simply preserve the current history , to the extent that they altered a timeline where their past enemies , the Rilnar and the Zahl , lived on a peaceful near - utopian planet , in favor of a timeline where the two were engaged in a protracted and pointless conflict on the same planet , because the peaceful timeline restricted Krenim expansion . Having discovered ' log buoys ' created by " Voyager " during the original timeline that were protected from changes to history by Borg phase technology , the Krenim attempted to eliminate " Voyager " to prevent the crew affecting their history , but when this attack simply briefly fractured " Voyager " across multiple time periods in , they abducted a version of Janeway from the ship and manipulated her into becoming a leader of the Rilnar against the Zahl during the aforementioned planetary conflict . Having learned about the Krenim manipulation , " Voyager " managed to rescue the alternate Janeway , who was taken into an alternate past to raise her daughter – conceived with a Krenim who posed as a Rilnar to manipulate her – as part of an attempt by Q to make up for some of the hardships Janeway had endured .