For centuries there have been innumerable theories as to when and how the world might end. Here are some highlights gleaned from alleged prophecies:

In 960 Bernard of Thuringia, a German theologian, calculated 992 as the most likely year for the world's end. As the time approached, panic was widespread.

German astrologer Johann Stoffler predicted an overwhelming flood on February 20, 1524. Believers started constructing arks. One man is said to have been trampled to death by a mob attempting to board his specially built vessel. When nothing happened, the calculations were revised and a new date given—1588. That year also passed without any unusual rainfall.

Solomon Eccles was jailed in London's Bridewell Prison in 1665 for striding through Smithfield Market, carrying a pan of blazing sulfur on his head, and proclaiming doom and destruction. Although the end of the world did not follow, the Great Fire of London did, in 1666.

After studying both the Bible and the mystical messages of the Great Pyramid, in 1874 Charles Taze Russell, founder of the sect that became Jehovah's Witnesses, concluded that the Second Coming had already taken place. He declared that people had 40 years, or until 1914, to enter his faith or be destroyed. Later he modified the date to "very soon after 1914."

Herbert W. Armstrong, publisher of the magazine "The Plain Truth," declared that January 7, 1972, was undoubtedly the date to watch. The utter failure of his prediction did not diminish his zeal.

The 16th-century seer Nostradamus is said to have favored 1999 as the year of a Martian invasion, while an 18th-century French prophetess, Jeanne Le Roger, established the year 2000 as the definitive one.

More recently, Harold Camping, the Family Radio evangelist predicted the end of the world could be Friday, October 21, 2011.