HARRY POTTER fans will today mark the astounding proliferation of the epic book series, twenty years on from its most humblest of origins.

The world first met the young wizard-in-training on June 26, 1997, when a total of just 500 hardback copies of JK Rowling’s Harry Potter and the Philosopher’s Stone were released.

Yet, in just two decades since, the novel has spawned six sequels, totalling more than 500million copies sold, along with eight movies which together have grossed more than $8billion worldwide.

The Harry Potter franchise is now thought to be worth around $25billion, and can boast its own chain of themed sites at Universal Studios’ theme parks and a two-part West End stage play.

Few could have predicted its hegemony, when the words were first put to paper in the early 1990s by Rowling, then an unknown author.

The idea for first novel, which centres on a young Harry and his friends attending The Hogwarts School of Witchcraft and Wizardry, was first thought up while Rowling was on a train journey between London and Manchester.

She penned the first book sitting in The Elephant House – a small Edinburgh cafe which has since become a bit of a tourist attraction for diehard fans.

The story continued with the 1998 follow-up The Chamber of Secrets, which preceded The Prisoner of Azkaban in 1999.

Four more tales – The Goblet Of Fire, The Order Of The Phoenix, The Half-Blood Prince and The Deathly Hallows – completed the series between 2000 and 2007.

Indeed, many iconic scenes from the movies were filmed on location in the Scottish Highlands and on the west coast of the country.

Though it’s been ten years since the series was concluded, its popularity remains as fervent as ever, with sales trends at Amazon showing a jump in print and digital book sales of 140 per cent between 2015 and 2016.

Amazon UK spokesman Simon Johnson said: said: “The wizarding world of Harry Potter has captured the hearts of the nation and the world...Here’s to another 20 years of a nation potty about Potter.”

With kindle sales of the books, Southampton and Bristol are the most active areas of the UK, with Glasgow, Edinburgh and Aberdeen all appearing on the top 10 list.

Amazon has also sold enough copies of the Complete 8-Film Collection for fans to watch the films for a total of 975 years.

Closer to home, family quiz events at the Edinburgh Waterstones regularly sell out and fans are often seen queuing around the corner to get their hands on any material released, such as the script for The Cursed Child stage play.

Morag Smart, who runs the children’s department at the Waterstones on Rose Street, said: “The response has been huge. We are completely sold out for the giant quiz event tonight, and we’ve got people on the waiting list.

“We usually have a lot of families and people of student age and young adults coming along – as you can imagine, things can get quite competitive.

“But it’s always a lot of fun; I’m sure many will be coming along in full costume.”

She added: “Harry Potter has always been very popular here and we’ve had people out queuing all night for midnight openings.

“We’ve had people in tears too and there’s usually a lot of tourists who come in here from all over to buy up the whole set.”

Now test your knowledge with our Harry Potter quiz...

Harry Potter became a modern literary sensation in 1997.

And with an estimated 107 million copies of J.K. Rowling’s first book, The Philosopher’s Stone, alone having been sold, there’s a fair chance you’ve read at least one Harry Potter tale.

The books gave us flying cars and invisibility cloaks, Dementors and Dumbledore, spin off films, video games, toys - even a theme park in Orlando.

So unless you’ve spent the last 20 years locked up in Azkaban prison, it’s been hard to escape the boy wizard with the lightning bolt scar.

The question, though, is how well you know your animagus from your Zonko’s….

1.    Which piece of clothing did Harry Potter use to help grant house-elf Dobby his freedom from nasty owner Lucius Malfoy?  

2.    Journalist Reeta Skeeter first appeared in the Goblet of Fire after filing a highly over-sensationalised report of a Death Eater attack on Muggles. Which newspaper did she work for?

3.    J.K. Rowling famously penned chapters for her first Potter books while she sipped coffee at an Edinburgh coffee shop overlooking Edinburgh Castle. Which one?

4.    Naughty Lord Voldemort was also known as Tom Riddle, a half blood wizard who became the most evil dark lord of all time. Where in Edinburgh will you find a real ‘Tom Riddle’?

5.    In the Order of the Phoenix, Hagrid wins a precious dragon’s egg during a card game at which pub?  

6.    What’s J.K. Rowling’s full name?

7.    Grindylows appear during one of Harry’s challenges in The Goblet of Fire. What are they?

8.    Where will ‘floo powder’ take you?

9.    Ron Weasley had three brothers. What are their names?

10.  Harry lived with the Dursleys. Who played Mr Dursley in the Harry Potter movies?

Answers. 1. A sock  2. The Daily Prophet. 3. The Elephant House, George IV Bridge. 4. The grave of Thomas Riddell, who died in 1806 aged 72, is at Greyfriars Kirkyard. 5. The Hog’s Head. 6. Joanne Rowling. She later added a middle name ‘Kathleen’. 7. A pale green water demon found in Hogwart’s lake. 8. On a journey via the nearest fireplace. 9. Twins Fred and George, and Percy. 10. Richard Griffiths.