King Rilvvan K'ntarr was the ruler of Rydonni Prime and executive of Rythani Products, a company that supplied weapons to the Galactic Empire. K'ntarr was a corpulent man, and at some point after the Empire's fragmentation at the Battle of Endor he hosted a function in his mansion on behalf of Moff Caerbellak, who came to the planet to check on a prototype weapon Rythani Products was developing for the Empire.

The next day, K'ntarr held a parade in honor of the Moff. It was at this point that the Moff discovered the prototype had been stolen, and he threatened the lives of both the king and the planet's population to get it back. One of the All Terrain Armored Transports in formation during the parade turned out to have been commandeered by the very thief who stole the prototype, Sienn Sconn, along with K'ntarr's own daughter, Princess Kalieva K'ntarr. Sconn and Kalieva were able to escape with the prototype, but Kalieva turned out to have been working for Caebellak the entire time and planted tracking device on the prototype. Kalieva and Caerbellak assassinated K'ntarr and ruled Rydonni Prime together.