Some believe the world is coming to an end Friday -- on 12/21/12 -- which is when an important phase on the ancient calendar of the Mayan people terminates. Here's a look back at just some of the failed doomsday predictions through human history.

A group of Anabaptists, one of the many radical sects that emerged following the Protestant Reformation, assumed control of the German town of Munster in the 1530s and hailed it as New Jerusalem awaiting the return of Christ.

In 1806, a hen in the English town of Leeds began laying eggs on which the phrase "Christ is coming" was written. The hen's owner eventually admitted to writing the phrase on the eggs with acid and re-inserting them into the fowl.

Based off careful study of his Bible, New England farmer named William Miller led thousands of "Millerites" to believe that the world would end on April 23, 1843. When it didn't, the group disbanded and formed the Seventh Day Adventists.

In February 1835, Mormon church founder Joseph Smith told church leaders that he had spoken to God recently, and during the conversation learned that Jesus would return within the next 56 years, after which the End Times would begin promptly.

Halley's Comet -- In 1910, the New York Times and other newspapers spread mass panic when they claimed that everyone on Earth would be bathed in toxic gas and die when the planet passed through the tail of Halley's comet that year.

In 1963, Pentecostal pastor William Branham claimed he met with 7 angels who revealed to him the meaning of the 7 seals of the Book of Revelation. He predicted that Jesus would return to Earth in 1977, but was killed by a drunk driver in 1965.

Televangelist and Christian Coalition founder Pat Robertson shocked many in 1976 when he "guaranteed" that the world would end in 1982. He continues to make predictions on everything from the price of oil to terrorist attacks to this day.

David Koresh led his Branch Davidian sect to its doom in a compound near Waco, Texas, in 1993. Koresh convinced his followers that he was Christ and said they should hole up at at the compound to prepare for the end of the world. 

Heaven's Gate -- Claims of an alien spacecraft following the comet Hale-Bopp inspired a San Diego UFO cult named Heaven's Gate to conclude that the world would end soon. On March 26, 1997, 39 of the cult members committed suicide.

The French apothecary and reputed seer published a collection of prophecies, but one of his most famous read: "The year 1999, seventh month / From the sky will come great king of terror." Many thought that July 1999 was his vision of Armageddon.

Many thought the "Y2K bug," in which computers wouldn't be able to differ between 1900 and 2000 dates, would shut down the world's computers and data storage systems, leading to a nuclear holocaust and other catastrophic problems. It didn't.

God's Church minister Ronald Weinland predicted millions of deaths in his book "2008: God's Final Witness, going on to state that by the end of 2006 ".

The American pastor and Christan radio broadcaster famously predicted that the world would end on May 21, 2011, aka the date of the "rapture". He previously predicted that Judgment Day would occur on or about Sept. 6, 1994.