What if George Lucas and Lois Mcmaster Bujold came togethered and combined their respective sci-fi universes?
I assume, if the Expanded Universe from Star Wars is used, Barrayar would originally be located in the Unknown Regions of the main Star Wars galaxy (the so-called Galaxy Far, Far Away). Sometime before the year 27,000 BBY (27,000 years before the Battle of Yavin), human colonists traveling in sublight sleeper ships fom Corusant discovered and colonize Barrayar. Around the year 500 BBY, merchants or explorers from the Galactic Republic discover Barrayar.
In the tens of thousands of years in between, the human colonists or Barrayar evolve into a noble Vor class and a commoner preole class. People who show an affinity with the Force are killed or banished from society as outcastes, and Barrayarans develop an anti-mutant slant.
After being discovered by outsiders around 500 BBY, the Barrayarans are politically united under planetary Emperors of the Vorbarra dynasty and rapidly develop their technology up to mainstream galactic norms. Nevertheless, Barrayarans are very often prejudiced against non-human races, Force-users like the Jedi, and droids because they are sentient machines.
By 430 BBY, the Barrayarans have conquered Komarr, another human-dominated planet independent of the Galactic Republic and bordering the Unknown Regions. By 300 BBY, conflicts with the Jedi order and armed starships and troops of the Republic's paramilitary Judicial Forces occur over attempts of the Barrayaran Imperium's sometime attempts to conquer border worlds and systems of the Republic.
When Palpatine becomes Supreme Chancellor in 32 BBY, a peace treaty between Barrayar and the Republic is signed, and Barrayar and it's satellite planet Komarr formally join the Galactic Republic.
During the Clone Wars, the Barrayarans are generally pro-Republic and opposed to the Separatists and the Confederacy of Independent Systems, and when the Republic is transformed into the Galactic Empire in 19 BBY, Barrayar is generally pro-Imperial, thanks to the pro-Palpatine bias of the ruling planetary Vorbarra Emperor. By 5 BBY, Barrayaans of the Vor class are a leading source of military officers for the Imperial Navy, Imperial Army, and Stormtrooper Corp.
When the Alliance to Restore the Republic (Rebel Alliance) is in full-scale armed rebellion against the Empire by 0 ABY, most Barrayarans are pro-Imperial and anti-Rebel.
In 3 ABY, however, the new planetary Emperor Gregor Vorbarra and his close friend Miles Vorkosigan start a campaign of their planet covertly supporting the Rebel Alliance, and after the destruction of the second Death Star battlestation and Imperial defeat in 4 ABY, Barrayar suddenly becomes openly anti-Imperial.
It should be noted, however, that Barrayar does not join the New Republic.
In the period from 9 to 11 ABY, when the Galactic Empire briefly revives under Grand Admiral Thrawn and the reborn Emperor Palpatine, Barrayar officially switches back to a pro-Imperial course. In 11 ABY, the Barrayarans revert to the anti-Imperial stance.
In 15 ABY, Emperor Gregor Vorbarra and the Imperial Remnant under Grand Admiral Gilad Paelleon sign a peace and trade treaty. By this time, Barrayarans have become a lot more tolerant of non-humans, robotic droids, and Force-users like Jedi. The Vorkosigan family is a leading advocate of these changes.