When most people think of Halloween,

they think of trick-or-treating,

parades,

bobbing for apples

and other family-friendly activities.

But bet you didn't know the true story

behind the ancient origins of Halloween.

It all goes back some 2,000 years

to the ancient Celtic festival known as Samhain,

celebrated on November 1st.

On the night before Samhain,

people believed that the dead returned as ghosts.

They would leave food and wine on their doorsteps

to keep roaming spirits at bay,

and wore masks when they left the house

so they'd be mistaken for fellow ghosts.

The Christian church turned Samhain into All Saints Day

or All Hallows in the 8th century.

The night before became All Hallows' Eve,

later shortened to Halloween.

You've heard of trick-or-treating on Halloween,

but what about souling or guising?

All three of these traditions originated

in medieval Britain.

On All Souls' Day, November 2nd,

the needy would beg for pastries known as soul cakes.

In return, they would pray for people's dead relatives.

This was called souling.

In the medieval Halloween tradition of guising

young people would dress up in costumes

and accept food, wine, money and other offerings

in exchange for singing, reciting poetry or telling jokes.

In 19th-century America

Irish and Scottish immigrants revived these old traditions

The result was trick-or-treating.

At first, it was much more about the tricks,

in the form of pranks and hijinks,

than the treats.

It wasn't until the 1950's that the custom took on

its current, family-friendly, kid-centred form.

Today, Halloween is big business.

With US consumer spending more than 2.5 billion

on costumes annually.

Add in the candy and it's estimated that Americans

spend up to 6 billion on Halloween each year,

making it the second most commercial holiday after Christmas.

So whether you're a fan of tricks, treats, or trivia,

there's a bit of Halloween history we bet you didn't know.