Possibly as early as the 1830s, followers of the Latter Day Saint movement (also known as Mormonism), were practicing the doctrine of polygamy or "plural marriage". After the death of church founder Joseph Smith, the doctrine was officially announced in Utah Territory in 1852 by Mormon leader Brigham Young. The practice was attributed posthumously to Smith and it began among Mormons at large, principally in Utah where the Church of Jesus Christ of Latter-day Saints (LDS Church) had relocated after the Illinois Mormon War.