The clan of Mother Talzin was a substantial clan of Nightsisters situated on the planet Dathomir, and they were under the leadership of Mother Talzin. Because Talzin brought the once separate Nightsister covens together under her command, the clan essentially represented the whole Nightsister order and their culture. A number of covens functioned within this unified clan.
The Confederacy of Independent Systems decimated the clan, for the most part, during the Clone Wars. This occurred when General Grievous orchestrated a massacre against them. Consequently, Talzin's choices were viewed as the catalyst for the Nightsisters' downfall, with Grievous's destructive actions being seen as the demise of their civilization. However, other covens, like the Nardithi Nightsisters, had adopted the "Nightsister" title by the time of the Galactic Empire.