The Muggle-Born Registration Commission was set up by the Ministry of Magic following Lord Voldemort  takeover on 1 August,1997. The public goal of the Commission was to force all Muggle-born wizards and witches to register with the Ministry, then undergo interrogation as to how they "stole" their magical power from "real" wizards and witches. The true purpose of the Muggle-Born Registration Commission was to imprison and degrade Muggle-borns. Dolores Umbridge was the head of the commission.  The Commission had Muggle-borns who registered fill out questionnaires about their family history, and then wait for their trial behind bars in the Ministry of Magic. While awaiting trial, they were guarded by Dementors, and threatened with the Dementor's Kiss if they resisted. Trials were held by Commission head Dolores Umbridge, who was assisted byDeath Eater and head of the Department of Magical Law Enforcement Yaxley at times.