Harry Potter And The Half-Blood Prince, the sixth Potter pic, arrives in cinemas this week.

What better time, then, to take a look back at the film franchise and the books that started it all...

1. A Delayed Train

Even if you have just a passing awareness of the Harry Potter series, you likely know how it came about – author Joanne Kathleen Rowling (the middle bit’s from her grandmother for use as her pseudonym – she doesn’t have a second name) says it just fell into her head in 1990 on a busy – and late – train.

"I had been writing almost continuously since the age of six but I had never been so excited about an idea before.

“I simply sat and thought, for four hours, and all the details bubbled up in my brain, and this scrawny, black-haired, bespectacled boy who did not know he was a wizard became more and more real to me."

It would be five tough years writing in cafes and struggling to make ends meet before Harry Potter And The Philosopher's Stone nabbed her an agent and, after eight rejections, a publisher in the shape of Bloomsbury.

Rowling fashioned a world focused on her young wizard, an orphan who survived the attack that killed his parents and left him scarred for life with a lightning bolt on his forehead.

Six more books would be published – The Chamber Of Secrets, The Prisoner Of Azkaban, The Goblet Of Fire, The Order Of The Phoenix, The Half-Blood Prince, and the epic finale, The Deathly Hallows.

Each tome chronicles a year (or thereabouts – the later books tend to fudge the timing) in Harry’s life at wizarding school Hogwarts.

Initially unaware that he’s anything special, he’s brought to the magical seat of learning to discover that he is, in fact, a hero destined to defeat the evil that destroyed his mother and father – dastardly wizard Voldemort (or He Who Shall Not Be Named as scared wand-wavers prefer to refer to him).

As Harry grows into his destiny, his life gets ever more dangerous, but he also makes solid friendships with the likes of Ron Weasley and Hermione Granger.

Together the trio will have to solve riddles, battle magical beasts and, above all, stop Voldemort’s plan to return, achieve immortality and take over the world. The usual, then.

Even as she wrote the first book, Rowling also had the idea for the final epilogue, which has mutated into the scene found at the end of the seventh book, Deathly Hallows.

Why? A couple of unexpected character deaths and one other, who gets a reprieve from his creator.

The books became a massive publishing phenomenon, so it was only a matter of time before Hollywood came calling.

Next: The Philosopher's Stone