The True Church of Jesus Christ of Latter Day Saints or True Mormon Church was a denomination of the Latter Day Saint movement. It was founded in the spring of 1844 in Nauvoo, Illinois, by leaders dissenting from the Church of Jesus Christ of Latter Day Saints.
The Reformed Church's president was William Law, a former counselor to Joseph Smith (then President of the Church). Law was joined by his brother Wilson Law, Robert D. Foster, Charles A. Foster, Francis M. Higbee, Chauncey L. Higbee and Charles Ivins. Members of the Reformed Church believed that "Mormonism" as it had been originally practiced was true but that the practice of plural marriage in particular was a corruption. William Law did not claim to be a prophet, but merely the president of the church. The church taught that Smith was a "fallen prophet".
This group was responsible for printing the Nauvoo Expositor.