The Nyemarians originated as a species from the planet known as Nyemari.
A Duchess governed the Nyemarians, residing within the Nyemari Royal Palace. Reportedly, the spaceport located in the capital city of Anem was the most advanced and architecturally impressive spaceport throughout the Meridian sector.
During the period of the Galactic War, Nyemarians were fleeing a widespread civil war happening on Nyemari and were seeking shelter on any world that would take them in. However, a faction amongst them had sworn to execute any who deserted.
In the year 1 ABY, the planet of the Nyemarians was visited by the Heroes of Yavin, who were undertaking an operation on behalf of the Alliance to Restore the Republic. They managed to steal the access codes that would allow them entry to the Nyemari Imperial Military Installation directly from the Duchess's palace. After accidentally triggering a silent alarm, the Rebels escaped from the palace, pursued by members of the Royal guard riding 74-Z speeder bikes. The Rebels successfully evaded the guards and made their way back to the South Anem Spaceport, where they had hidden their ship, the Millennium Falcon, along with the Nyemarian Li Preni. Preni informed them of their pursuit, leading the Rebels to confront the Glymphid who had been tracking them. The Glymphid then played a hologram message from Rezi Soresh, instructing the Rebel pilot Luke Skywalker to meet with Soresh; the Glymphid then died as a result of a delayed-release poison, and the Rebels departed from Nyemari.
Nyemari possessed an Imperial Military base, in addition to its advanced spaceport. A Wookiee disguised as a Palace guard did not arouse suspicion.
The Nyemarians were first featured in Alex Wheeler's 2010 novel, Rebel Force: Uprising. The book offers little detail concerning their physical appearance, only implying that they are either Humans or humanoid in nature.