A quorum established in 1835 whose primary responsibility was missionary work. The quorum was originally established to be equal in authority to the First Presidency and Quorum of the Twelve and was comprised of seventy members. Following the death of Joseph Smith, the Seventy were considered inferior to the Quorum of the Twelve and First Presidency and acquired administrative authority beyond missionary responsibility. They are considered part of the General Authorities of the LDS Church and preside over all the church under the direction of the First Presidency and Twelve.1
1 A Man Without Doubt, 179.