The most popular theory about Valentine's Day origin is that Emperor Claudius II didn't want Roman men to marry during wartime. Bishop Valentine went against his wishes and performed secret weddings. For this, Valentine was jailed and executed. While in jail he wrote a note to the jailor's daugter signing it "from your Valentine".

In Victorian times it was considered bad luck to sign a Valentine’s Day card.

Based on retail statistics, about 3 per cent of pet owners will give Valentine’s Day gifts to their pets.

About 1 billion Valentine’s Day cards are exchanged each year. This makes it the second largest seasonal card sending time of the year

If you’re single don’t despair. You can celebrate Singles Awareness Day (SAD) instead.

Meant as an alternative to Valentine’s Day, the holiday is for single people to celebrate or to commiserate in their single status.

Or you could pop over to Finland where Valentine’s Day is called Ystävänpäivä, which translates into “Friend’s day”. It's more about remembering your buddies than your loved ones.

Many believe the X symbol became synonymous with the kiss in medieval times. People who couldn't write their names signed in front of a witness with an X. The X was then kissed to show their sincerity.

Girls of medieval times ate bizarre foods on St. Valentine's Day to make them dream of their future spouse.

In the Middle Ages, young men and women drew names from a bowl to see who would be their Valentine. They would wear this name pinned onto their sleeves for one week for everyone to see. This was the origin of the expression "to wear your heart on your sleeve."

In 1537, England's King Henry VII officially declared Feb. 14 the holiday of St. Valentine's Day.

Physicians of the 1800s commonly advised their patients to eat chocolate to calm their pining for lost love.

Richard Cadbury produced the first box of chocolates for Valentine's Day in the late 1800s.

More than 35 million heart-shaped boxes of chocolate will be sold for Valentine's Day.

More than 35 million heart-shaped boxes of chocolate will be sold for Valentine's Day.

15 percent of U.S. women send themselves flowers on Valentine's Day.

Over $1 billion worth of chocolate is purchased for Valentine's Day in the U.S.

Over 50 percent of all Valentine's Day cards are purchased in the six days prior to the holiday, making Valentine's Day a procrastinator's delight.

The red rose was the favorite flower of Venus, the Roman goddess of love.

Red roses are considered the flower of love because the color red stands for strong romantic feelings.

189 million stems of roses are sold in the U.S. on Valentine's Day.

Women purchase approximately 85 percent of all valentines day gifts

Teachers will receive the most Valentine's Day cards, followed by children, mothers, wives, sweethearts and pets.

220,000 is the average number of wedding proposals on Valentine's Day each year.

Every Valentine's Day, the Italian city of Verona, where Shakespeare's lovers Romeo and Juliet lived, receives about 1,000 letters addressed to Juliet.