Brigham Young was an early convert to the Mormon Church, which was founded in 1830 by Joseph Smith, Young’s relative by marriage. Young quickly advanced within the Mormon hierarchy, becoming president of the Quorum of the Twelve Apostles (the governing body of the church). After Smith’s death in 1844, various leaders asserted their claims to become his successor. Rather than settling on a single candidate, the Mormon Church splintered into sects, each with its own leader. Young became the president of the largest faction, then centered in the Mormon city of Nauvoo, Illinois. This faction became the modern-day Church of Jesus Christ of Latter-day Saints (LDS). In 1846 conflict with the local population made the Mormon position in Illinois untenable, so Young ordered the church members to move westward, as many Americans were doing at the time. They established a new LDS center in the Utah Valley around the Great Salt Lake. There Young became the autocratic ruler of a Mormon state whose isolation made it in its early days a virtually independent country.