The unnamed house had previously produced high-powered ships. Valkris discovered that she liked to meditate in a high gravity field. While in the presence of non-Klingons, Valkris wore a headcloth that covered most of her head other than her eyes. This was a family custom. She kept a dueling dagger on her at all times. The sheath of the dagger was encrusted with flakes of various minerals so finely cut, they appeared as gemstones. It also contained a thick fringe entwined with discs of multi-colored mica. Each disc had a different significance to Valkris as they represented various family members. It was one of Valkris' only possessions.
Eventually, Valkris became one of the few females to lead a Klingon Great House, having been chosen for the honor over her brother Kiosan. The shame of this drove Kiosan to dishonorable behavior. Kiosan's dishonor had tainted the House so badly that Valkris was forced to disown him. During this time, she became involved with Commander Kruge, feeling that he would help her regain some of the honor she lost due to Kiosan's actions. For his part, Kruge admired the young woman as a fierce warrior.
After the Klingon Empire became aware of the existence of Project Genesis, Valkris undertook a mission to obtain a copy of the Project Genesis data. She was able to obtain a report filed by then Admiral James T. Kirk, who had included a summary of the Genesis Project data. Once she had seen the data for herself, Valkris obtained transport on board the freighter Merchantman, which rendezvoused with Kruge's Bird-of-Prey. Valkris transmitted the data to Kruge, telling him that he would find the data useful.
Kruge realized that Valkris had seen the data. Telling her that it was unfortunate, Kruge proceeded to attack and destroy the Merchantman, killing Valkris as well as most of the Merchantman's crew. (TOS movie, novelization & comic adaptation: Star Trek III: The Search for Spock)