It’s believed that this superstition began in the Middle Ages. Some think it’s related to the Last Supper, when 13 people were present at the meal before Jesus’s crucifixion on Good Friday. Others think it’s related to the Knights Templar, who were arrested for heresy on Friday 13 October 1307 (exactly 710 years ago today, in fact).
The number 13 has been considered unlucky for millenia, and by many different cultures around the world. The Mayans thought that the 13th ‘baktun’ (a period equivalent to almost 400 years) would spell the end of the world – however, this came and went in 2012.
Fridays are also considered unlucky by a number of cultures, especially Christian ones (probably due to the aforementioned crucufixion). However, the first written record we have of the number 13 and Friday being unlucky in conjunction only dates from the 19th century:
“He [Italian composer Gioachino Rossini] was surrounded to the last by admiring friends; and if it be true that, like so many Italians, he regarded Fridays as an unlucky day and thirteen as an unlucky number, it is remarkable that on Friday 13th of November he passed away.”
Despite its somewhat hazy history, the fear of Friday 13th is very real – it’s even been given a scientific name (paraskevidekatriaphobia – from the Greek words Paraskeví, meaning Friday, and dekatreís, meaning 13). Many people choose to stay in bed to reduce the likelihood of accidents, and it’s estimated that in the US, $900 million is lost in business each time as a result.