Fear of the number 13 is called triskaidekaphobia.
Fear of Friday the 13th is paraskevidekatriaphobia.
Fear of the number 13 was known in both Old Norse and Ancient Babylonian myths.
Old Norse mythology tells of a banquet that ended in disaster after Loki arrived as an uninvited guest, raising the total number from 12 to 13.
For the Babylonians the fear was linked to a belief that the Sun needed to be kept separate from the 12 Zodiac signs.
According to the 1894 edition of Brewer's Phrase And Fable: 'The Turks so disliked the number 13 the word is almost expunged from their vocabulary.'
In Christian tradition, fear of Friday the 13th stems from the day of the Crucifixion (Friday) and the number at the Last Supper (13).
Despite these origins, the Friday the 13th superstition dates back only to the Middle Ages.
No more than three Friday the 13ths can occur in a single year.
The last year that had three Friday the 13ths was 2009; the previous time was 1998.
The longest period that can pass without a Friday the 13th is 14 months.
The first time DNA evidence was used in a British court to secure a conviction for rape was on Friday 13 November, 1987.
Louis XIII of France (1601-43) was so fond of the number 13 that he married 13-year-old Anna of Austria.
By the 19th century, however, the number had become so feared that a society of French aristocrats was formed called the quatorziennes ('14ths'), who were available to come at short notice to dinners where 13 had turned up.
Even in the modern supposedly enlightened age, it has been estimated that fear of the number 13 costs the US economy a billion dollars a year in absenteeism, cancellations and reduced commerce on the 13th days of the months.
Anyone seeking supporting evidence for the superstition, however, need look no further than the British National Lottery, where the number 13 has been picked less frequently than any other.
The wedding anniversary corresponding to 13 years' marriage is called a Lace Wedding.
The spoil from digging the Channel Tunnel between England and France would have filled Wembley Stadium 13 times.