It’s a day of bad luck and superstition for many people in the Western world.
Friday the 13th is so ominous that there are even official terms to describe the date-based phobiaβparaskevidekatriaphobia and friggatriskaidekaphobia.
Paraskevidekatriaphobia (say that five times fast) was coined by Dr. Donald Dossey as the medical term for the extreme irrational fear of Friday the 13th.
Friggatriskaidekaphobia is a combination of Frigga, the Norse goddess from which the name “Friday” originated, and triskaidekaphobia, which is the fear of the number thirteen.
But how did Friday the 13th become so infamous? I was curious about the origins of the unlucky date, and here’s what I uncovered.

Friday and the Number 13 Used to be Lucky
Rewind a few thousand years to the ancient pagan days of Europe. We can trace the word “Friday” back to the old English word frΔ«Δ‘edΓ¦Δ‘, meaning “day of Frigg” in honor of the highest goddess worshipped by the Norse culture.
Frigg (also sometimes called Frigga) was married to Odin, and the two ruled over Asgard together. The goddess Frigg represented love, marriage, fertility, and motherhood. She offered protection to homes and families that were loyal to her.
Freya was a similar goddess who is often conflated with Frigg. They shared characteristics as goddesses of love and fertility, but Freya was also a war maiden who would lead Valkyries to gather fallen warriors from the battlefield. She rode a chariot pulled by two male cats, Bygul and Trjegul. In some stories, they’re blue or gray, and in others, they’re black.
(Freya’s connection to cats may have contributed to the black cat superstition).
Frigg and Freya were both widely worshipped across Europe, and the goddesses’ power over love and fertility made Friday a lucky day for marriage for the Norse and Teutonio people.

The number thirteen was considered sacred, likely due to its connection with lunar and menstrual cycles in a single year. It could also reflect the number of days between menstruation and ovulation, which was important for cultures that honored fertility and feminine power.
For example, the Venus of Laussel carving, which is estimated to be approximately 25,000 years old, shows a naked woman holding a horn or cornucopia that has thirteen notches on it. Her large breasts and hips are the typical form to represent a fertility goddess during that time period.
So, if Friday was a sacred day honoring Frigg, and the number thirteen was so important to ancient cultures, how did Friday the 13th become synonymous with misfortune in modern civilization?
A Twist of Fate: How Friday and the Number 13 Became Unlucky
Like most superstitions, it’s difficult to pinpoint the exact origin of the Friday the 13th curse.
Over time, the sacred number thirteen became an unlucky numeral.
The Norse god of mischief, Loki, was said to have crashed a Valhallan banquet of twelve gods, making him the thirteenth god in attendance. He deceived Hodr into shooting his brother Balder with a mistletoe-tipped arrow, instantly killing the god of light and joy and plunging the world into darkness.
This is the most likely cause of thirteen starting to become associated with bad luck, which only worsened in the Christian era. During the Last Supper, the infamous Judas Iscariot was the thirteenth guest to arrive. He later betrayed Jesus, leading to Jesus’s crucifixion and death.

The Christian faith also instilled a negative view of unlucky Fridays, as that was allegedly the day of the week that Adam and Eve consumed the forbidden fruit from the Tree of Knowledge, Cain murdered his brother Abel, the Temple of Solomon was destroyed, and Noah’s ark set sail during the Great Flood.
Good Friday was the only Friday that was… well, good.
When Religions Collide
The clash of Christianity and pagan religions started to turn Friday and the number thirteen further in the wrong direction.
Paganism, which worshipped femininity and strong goddesses among their many deities, stood at odds with the patriarchal Christian faith, which opposed the multiple deities as well as other traditions such as the sacredness of Frigg’s day, the number thirteen, and the unholy practice of praying to heathen gods for sex, fertility, love, magick, and protection.
Pagans wouldn’t easily relinquish their beliefs, so in order to convert them, Christian leaders pushed a campaign that branded goddesses and the women who worshipped them as witches.
Frigg was allegedly banished to a mountaintop in shame when Christianity swept through Norse and Germanic tribes. She was labeled as a witch. People believed that every Friday, she summoned eleven other witches and the devil β totaling thirteen evil beings β so they could plot their revenge and spread misfortune.
The Christian faith successfully rewrote the narrative. The once-powerful goddesses of love and fertility were viewed as spiteful, sinful witches, as were their female followers.
In Britain, people who had been convicted and condemned to death were usually hanged on a Friday, which became known as Hangman’s Day.
Putting it All Together: The Birth of Friday the 13th Superstitions
In the grand scope of history, considering we’re looking back at the last 25,000 years or so, Friday the 13th itself is a modern phenomenon.
In 1907, novelist Thomas W. Lawson published a popular novel called Friday, the Thirteenth. The book featured an unscrupulous broker who created a Wall Street panic and crashed the stock market on, you guessed it, Friday the 13th.
This was the first instance of the specific date of Friday the 13th becoming synonymous with misfortune. Prior to Lawson’s novel, Friday and thirteen were both regarded as unlucky for different reasons, never pieced together as a specific date.
Slashing into the 1980s came Jason Voorhees, the hockey-masked killer in the “Friday the 13th” horror movie franchise.
The Da Vinci Code, a mystery thriller written by Dan Brown, furthered the superstitions by popularizing the false claim that Friday the 13th originated with hundreds of Knights Templar members being arrested on Friday, October 13, 1307.
Modern-Day Superstitions
Here we are, now in the 21st century when Friday the 13th is widely acknowledged to be the unluckiest day of the year in western culture.
Lucky us β there’s at least one Friday the 13th every year. Many years have two or three. If a month begins on a Sunday, beware! Friday the 13th is coming.
Regardless of how you feel about the date, friggatriskaidekaphobia affects millions of people. The extremely superstitious have been known to alter their normal routines, and businesses usually see a loss of revenue on that day, especially airlines. However, studies haven’t shown any measurable spike between the number of accidents that happen on Friday the 13th versus any other day.
Triskaidekaphobia is even more common. It’s not unusual to see many high-rise buildings “skip” the thirteenth floor and jump from twelve to fourteen. Many airports don’t have a Gate #13, and some airlines don’t even have a Row 13 on their planes. Crazy, right? Especially when you think about how sacred the number thirteen was to our distant ancestors praying for family and fertility.
But Friday the 13th isn’t unlucky around the globe. In Greek and Hispanic cultures, it’s Tuesday the 13th that’s unlucky. And in Italy, Friday the 17th is the day of bad luck instead of the 13th.
Is Friday the 13th a lucky or unlucky day for you? Have your views changed after learning about the history behind the superstition?
Image credits:
Venus of Laussel: By photo 120, Εuvre dont l’auteur est mort depuis environ 25 000 ans – Own work, CC BY 3.0, https://commons.wikimedia.org/w/index.php?curid=5044488
The Last Supper: By Leonardo da Vinci – Online Taken on 23 July 2013, Public Domain, https://commons.wikimedia.org/w/index.php?curid=50410532
Award-winning fantasy author, freelance writer, spiritual explorer, and sole founder of Green Witch Lunar Witch. She created her first website in 2016 and published her first novel two years later. Sara spends most of her time writing, creating, and daydreaming.