The Mitth family, also known as the Eighth Ruling Family and House Mitth, was one of the Ruling Families of the Chiss Ascendancy. Along with the Second Ruling Family, the Eighth Ruling Family had charge of military affairs. Every Chiss Ruling Family was apparently associated with a specific color, and that of the Eighth Ruling Family was a dark burgundy red.
As with all Ruling Families, membership and status within the group was defined partially by blood descent, but partially also by merit. The brothers Mitth'ras'safis and Mitth'raw'nuruodo, born commoners, became members of this Family by a complex process of adoption, which seems to have involved their being attached as temporary merit adoptives, then declared Trial-born, and finally matched permanently to the bloodline, a process that may have involved marriage to female members of the kin-group. By 27 BBY, Thrass, the elder brother, was a Syndic of the Family while Thrawn was a Force Commander in the Chiss Expansionary Defense Force.
Kres'ten'tarthi, a Commander in Syndic Mitth'raw'nuruodo's Household Phalanx. Though never legally affiliated with the Mitth family, Kres'ten'tarthi did wear the colors of them.
At some later date, Thrawn likewise became a Syndic of the Family, as in 19 ABY, Luke Skywalker and Mara Jade encountered warriors from a Chiss Household Phalanx on Nirauan, identifying themselves as warriors serving "Syndic Mitth'raw'nuruodo", and wearing the burgundy colors of the Family. The siblings had, in fact, planned to give Thrawn the title of Ranking Distant, before his exile.
Though none of the Siblings, or even cousins, supported Thrawn's Empire of the Hand, Ranking Distant Mitth'ara'sopra did quietly support the Hand. However, after Thrawn's death, she was no longer as passionate in her support. Thrawn still regarded himself as a member of the family, using the Mitth in his name despite his exile. Many lower members(Merit adoptives, military officers and even Syndics) supported Thrawn in the name of the Mitth family.