Today is Friday the 13th, and many people will be nervously watching the skies for sudden lightning strikes or falling anvils. But where does our superstition surrounding this day, known as paraskevidekatriaphobia, originate from?

And why is there such apprehension surrounding the number 13? This fear, called Triskaidekaphobia, is not just of concern to some people a few days of the year – it drives them to avoid using 13 as much as possible in daily life.

Friday 13 in history and fiction

Though folklorists claim there is no written evidence for the superstition before the nineteenth century, the date has long been connected to notorious events in history and religion.

According to Catholic belief, one of the most significant events in their religion - the crucifixion of Jesus Christ - took place on a Friday the 13.

Geoffrey Chaucer also made reference to the apparent unluckiness of the day, recording in his Canterbury Tales that it was bad luck to start a journey or a project on a Friday.

One of the most popularised myths attempting to explain the origin of the Friday 13 superstition stems from events on Friday 13 October 1307, when hundreds of Knights Templar were arrested and burnt across France.

This myth caught the public’s attention after it was used by Dan Brown, among other historical fiction writers, and has been peddled endlessly by conspiracy theorists linking the Knights Templar to everything from Freemasonry to the Holy Grail.

Friday the 13th and other superstitions Show all 9 1 /9 Friday the 13th and other superstitions Friday the 13th and other superstitions Friday 13th The number 13 has long been considered unlucky. In numerology, 12 is considered complete (12 hours, months, zodiac signs) - and 13 is irregular. There were also 13 guests at The Last Supper (the 13th being that traitor Judas). Jesus was also crucified on a Friday. A Dutch study from 2008 apparently showed that fewer accidents and reports of fire occurred on the date as people were generally much more cautious. Friday the 13th and other superstitions Black cats The beliefs surrounding black cats vary around the world, with some cultures considering them to be lucky and others a bad omen. The most widespread Western belief is that if a black cat crosses your intended path, bad luck will befall you. Black cats have long been associated with witches, and during the Middle Ages these superstitions even led people to kill them. This was then said to increase the population of rats and hence the spread of the Black Death (Bubonic Plague). Friday the 13th and other superstitions Breaking a mirror One of the longer sentences dished out by Lady Luck, the superstition follows that breaking a mirror will leave you doomed for seven years. The reflection is said to represent the soul, so damaging a mirror corrupts the soul of the one that broke it. Some believe that the reason for the length of the punishment is that the Romans (the first glass mirror-makers) thought life renewed itself every seven years, so the soul wouldn't be fully restored until the next cycle had passed. Friday the 13th and other superstitions Opening an umbrella indoors Back in Ancient Egypt when umbrellas were used as protection against the sun, they were designed to capture Nut's (the goddess of the sky) essence. To open one indoors would also be to insult Ra and invite his wrath on everyone in the household. Another myth surrounding the superstition is that it was invented specifically to cut down on the number of accidents that sprang from the pointy and dangerous metal spokes on umbrellas in Victorian England. Friday the 13th and other superstitions Magpie To see a single Magpie is considered unlucky, so you may hear people greeting the bird with 'Hello Mr Magpie. How/Where is your wife?' Magpies are often seen as sneaky due to their penchant for shiny objects, such as jewellery and coins, their lack of a pretty singing voice, and their habit of eating the eggs from bird nests. In Scotland they're considered a sign of impending death, but in China spotting one is regarded as good luck. Generally they're not all bad though, only when alone: The old rhyme goes:

'One for sorrow, Two for joy, Three for a girl, Four for a boy, Five for silver, Six for gold, Seven for a secret never to be told.' Friday the 13th and other superstitions Spilling salt Back in the day, long before processed meals were invented, salt was an extremely rare commodity and so to spill it was considered a waste of money. As a valuable preservative, it was also linked with longevity so some cultures believed that spillage could affect your own health. If you look closely at Leonardo da Vinci's The Last Supper, you might also spot that Judas has spilled the salt. A German proverb holds that 'whoever spills salt arouses enmity', with the best antidote being to toss a pinch of the spilt salt over your left shoulder, into the face of the Devil who lurks there. Friday the 13th and other superstitions Full moon Full Moons are traditionally linked with temporary insomnia and insanity due to the folklore that madness can occur in cycles with the moon, hence the term lunatic or lunacy. It was also thought that to sleep in direct moonlight caused madness or blindness. The full moon is of course associated with lycanthropy as the mythological werewolf is said to appear whenever one appears...A study by the Bradford Royal Infirmary even found that there was a significant increase in animal bites during a full moon over a certain period. Friday the 13th and other superstitions Treading on cracks in pavement 'Step on a crack, break your mother's back' The superstition of stepping on cracks in the pavement is said to originate from an ancient fear of letting the soul out of the Square, as the four corners are an ancient symbol of balance and perfection. It also makes for some interesting walking habits. Friday the 13th and other superstitions Never say 'Macbeth' According to a theatrical superstition called the Scottish curse, speaking the name Macbeth before a performance will cause tragedy - as a result the lead character is often referred to as the Scottish King. Those who believe in the curse claim that real spells are cast in the three witches scene. Productions of Macbeth are said to have been plagued with accidents, many ending in death. The legend of the curse dates back to the premiere of the play when an actor died because a real dagger was mistakenly used instead of the prop. British Museum

Unlucky 13?

The origins of Triskaidekaphobia – the fear of the number 13 – could be traced back to the 19th century belief that Judas Iscariot sat in the 13th place at Jesus’s table at the Last Supper.

Along with Jesus, there were 12 disciples at this meal, and Judas has come to represent betrayal and bad luck in Western societies. Even if there is no direct biblical evidence linking Judas to the 13th place at the table, the number of guests at the Last Supper and its significance in the Christian religion could have been enough to cement the idea of 13 as an unlucky number in Western cultures, particularly if this idea was promoted by the superstitious Victorians.

Modern day incarnations

Ironically, the superstition of the event may be linked back to an American club that attempted to debunk the superstition surrounding the number 13 and its associated bad luck date.

The Thirteen Club first met on 13 September 1881 (a Wednesday) and determined to actively flout any and all established ‘superstitions’ they knew about.

With this in mind, the group of 13 would meet on the 13 of each month, sit 13 to a table, break mirrors, spill salt with abandon, and walk under ladders – all while carefully recording how many members died.

Over the years the group grew to roughly 400 members – including a number of US presidents – but the groups notoriety just added to the date’s significance in the public psyche.

Then, in 1907, eccentric stockbroker Thomas Lawson published a book called Friday the Thirteenth. It detailed an evil business’s attempts to crash the stock market on the unluckiest day of the year. The book was a sell-out and in 1916 made into a feature-length film.

Finally, the myth acquired the first seal of Hollywood in 1980 when Paramount Pictures released Friday the 13. Fridays would not be the same again, after Jason proceeded to slash his way across a summer camp and US box offices.

The 'statistics' of Friday 13th

There have been various studies released over the years that either prove or disprove the Friday 13 myth.

In 1993 a British Medical Journal study claimed there was a “significant” increase in incidences on a Friday the 13, but the author of the study later confessed it was “a bit of fun” as traditional in the Christmas edition.

Meanwhile, Dutch researchers found you were actually less likely to be injured on Friday 13th. The study hypothesised that people were preventively more careful on the day as a result of the superstition.

Not Friday the 13th but Tuesday the 17th?

As it turns out, paraskevidekatriaphobia is mostly an American and English fear.

Italians previously used to be far more concerned about Friday the 17th, although with the Americanisation of the country this has largely shifted to 13th for younger generations.