Founder of Mormon church Joseph Smith wed 40 wives

Joseph Smith's martial history had always remained a mystery but it has been revealed that he married women who were already the wives of his followers - despite maintaining for nearly 200 years that he was monogamous.

The Church of Jesus Christ of Latter-Day Saints had previously tried to gloss over aspects of its history, including the polygamy practiced by Mr Smith and Brigham Young.

Mr Young helped found the headquarters of the Mormon church in the Salt Lake City in Utah, United States.

A church essay entitled "Plural Marriage in Kirtland and Nauvoo"wrote: "Joseph married many additional wives and authorized other Latter-day Saints to practice plural marriage," before noting, "careful estimates put the number between 30 and 40."

The church has been widely criticised for its treatment of women, black people, who it barred from the higher priesthood until 1978, and homesexuals, who were banned from its temples if they were sexually active.

Mr Smith's wives were mostly between the ages of 20 and 40, but Helen Mar Kimball, the daughter of close friends, was "sealed" to him several months before she turned 15.

The essay, part of a collection issued over the past year, said: "Plural marriage was difficult for all involved. For Joseph Smith's wife Emma, it was an excruciating ordeal."

The church, founded in 1830, banned polygamy in 1890 when the US government threatened to deny Utah statehood.