House Ginaz from the planet Ginaz was a Great House of the Landsraad during the time of the Faufreluches. It was an ally of House Atreides during the time of Duke Leto the Just. They were defeated in a War of Assassins by House Moritani of planet Grumman.
It is noted in Dune that House Ginaz are "one-time allies of Duke Leto Atreides" and are "defeated in the War of Assassins with Grumman." Duncan Idaho is noted to be a "Swordmaster of the Ginaz," which leads to his body later being sold to the Tleilaxu as "a master swordsman, an adept of the Ginaz School.