The first church conference is held with twelve officers called "apostles" by common appellation in their elders certificates and elsewhere. Eleven are among the special witnesses to the Book of Mormon in 1829. At the conference Joseph Smith performs the church's first miracle by casting the devil out of Newel Knight who afterward sees a vision of the Father and Son. This month Satan also appears to Smith as "an angel of light" and is exposed by the Archangel Michael, and Smith dictates a revelation on the "vision of Moses" which describes a visionary deception by Satan anciently.
[On This Day in Mormon History, http://onthisdayinmormonhistory.blogspot.com]