Blockade of the Rimma Trade Route In the year 3681 BBY , the Rimma Trade Route was blockaded by the Sith Empire in an attempt to strangle the resources of the Galactic Republic . The action was one of the earliest conflicts of the Great Galactic War , and occurred shortly after the Empire ' s return to the known galaxy . As part of the Sith Emperor ' s plan to secure the galaxy ' s Outer Rim Territories , the Rimma super - hyperroute was locked down , which resulted in further Republic losses and interior political turmoil . While Republic forces in the Outer Rim suffered from a lack of supplies and reinforcements — particularly those in the embattled Minos Cluster — military leaders organized efforts to retake the Rimma Trade Route . After the Republic Army ' s first unsuccessful counterattack , the blockade was ended in 3680 BBY , when a fleet of the Republic Navy regrouped in the Seswenna sector and launched a second assault . The attack succeeded in breaking the Empire ' s hold on the route , thereby allowing the Republic to ship war materiel and reinforcements to Outer Rim battlefronts . Prelude . After more than a millennium of exile in the galaxy ' s Unknown Regions , the ancient Sith Empire returned to galactic notoriety in 3681 BBY in a new and robust form intent on the destruction of the Galactic Republic and the Jedi Order in a conflict that became known as the Great Galactic War . The Sith ' s leader , known only as the Sith Emperor , led his people in a campaign to secure the Outer Rim Territories in a swift and unforgiving offensive . After highly successful efforts in the Tingel Arm region and the recapture of the Sith ' s ancestral homeworld of Korriban , the Empire pressed its advantage and widened its offensive . Imperial forces invaded the Minos Cluster and enacted a mass slaughter on the Republic shipyard world of Sluis Van . Meanwhile , the Imperial Armada set its sights on the highly valuable Rimma Trade Route that connected the planet Abregado - rae in the Core Worlds to the distant Outer Rim . The blockade . In the first year of the war , the Sith ' s navy moved onto the Rimma super - hyperroute , successfully blockading the path by stationing the bulk of its fleet in the Seswenna sector , near the edge of the Mid Rim . With the vital and extensive hyperspace lane under their control , the Imperials strangled Republic supply lines in a highly effective operation that strained the Jedi defenders in the Minos Cluster and the forces of the Republic across the Outer Rim . The repercussions that weighed heavily on the Republic ' s defense force were also felt on the capital world of Coruscant , where the blockade contributed to a panic in the upper echelons of galactic politics . The Republic Military eventually staged a counterattack in the Seswenna sector but suffered a devastating loss that saw the capture of hundreds of Republic soldier s . Although news of the failed assault was greatly demoralizing for other Republic forces in the Outer Rim that relied on supplies from the Rimma Trade Route , the fleets of the Republic Navy were able to regroup by 3680 BBY and launch yet another attack in the Seswenna region . That effort proved effective , and the Sith blockade of the trade route was broken , freeing up transport for Republic supplies to the Outer Rim Territories . Aftermath . Although it was ultimately broken by the naval forces of the Republic , the year - long blockade of the Rimma Trade Route was a highly successful endeavor , particularly in conjunction with the Imperial victory in the Sluis sector . Additionally , it allowed for the Sith to gain an early advantage over the Jedi Order in the Empire ' s attempt to acquire the resource - rich Minos Cluster . The series of losses for the Republic forced government leaders and the Jedi High Council to organize an emergency defense summit in an attempt to organize and prioritize the galaxy ' s military resources . The meeting , held by the Galactic Senate , ended in political gridlock , as senators and other representatives refused to take part in deliberations if they felt that their constituent worlds were overlooked . While the political crisis continued in the highest echelons of the Republic government , the Empire moved onward to sweep the Outer Rim Territories in their widely successful war . In 3671 BBY , ten years after their initial seizure of the Rimma Trade Route , the Empire returned to the Seswenna sector and seized the region , sealing their dominion over much of the Outer Rim . The blockade of major hyperspace lanes became the most effective tactic in the war , particularly when the Mandalorian warrior clans entered the conflict on behalf of the Empire . In 3661 BBY , the Mandalorians seized the Hydian Way ; with the Mandalorian ' s blockade of the Hydian and the Sith ' s control of the Rimma Trade Route in the Seswenna sector , the Empire had control of two of the galaxy ' s most vital supply lines . The Kel Dor Jedi Knight Gnost - Dural kept a journal during the Great Galactic War that included references to the Rimma blockade , as well as his own feelings of relief after it was originally broken in 3 , 680 BBY ; as a Republic defender in the Minos Cluster , Gnost - Dural and his comrades relied upon reinforcements and supplies that were shipped along the hyperroute . After the conclusion of the war with the signing of the Treaty of Coruscant in 3653 BBY , Gnost - Dural ' s journal , as well as a scholarly holodocumentary produced by the Kel Dor on the early days of the war and the Rimma Trade Route blockade , were submitted to the Jedi Archives on Tython for record - keeping purposes . Behind the scenes . The blockade of the Rimma Trade Route was created as part of the back - story for the LucasArts – BioWare video game , " " . The event was first mentioned on the Sith Empire ' s in - universe Holonet page , as found on " The Old Republic " website . A mention of the blockade was later made in the sixth entry of the " Galactic Timeline " , titled " " . The timelines serve as a historical accounting of the Great Galactic War as compiled by Jedi Master Gnost - Dural , whose voice is provided by actor Lance Henriksen . " Onslaught of the Sith Empire " was released on January 22 , 2010 . Other information on the blockade , including the first two battles of the Seswenna sector , were provided in " The Journal of Master Gnost - Dural " , a book included in the collector ' s edition of " Star Wars : The Old Republic " , released December 20 of 2011 .