As a child, Sheldon Hall was taken with a group of friends to the pictures at the Carlton in Front Street, Tynemouth. The cinema has long gone, replaced by an estate agent's office, but the memory of the film he saw lingers on.

He was only seven or eight but Zulu, "a true recreation of colourful history" as star and producer Stanley Baker described it, certainly made an impression.

The film became something of an obsession: one that's culminated in writing a book, Zulu - With Some Guts Behind It, about one of the most popular British movies ever made.

The picture recounts the true story of the Battle of Rorke's Drift in 1879 when around 150 British soldiers fought for 12 hours to defend an isolated mission against an attack by 4,000 Zulu warriors in South Africa.

Hall, a former film and theatre reviewer for The Northern Echo, has produced an epic book about an epic film. One that York-born composer John Barry, who wrote the score for Zulu, describes quite rightly in his foreword as an "incredibly thorough book". Every aspect of the production, from the original John Prebble short story, through script development and financing to the marketing and premiere, has been investigated by Hall in a project that took him four years to complete.

His work hasn't stopped with its publication as he's introducing special screenings of the film - released in 1964, the year Hall was born - around the country. He introduced a National Film Theatre showing in London as part of a Michael Caine tribute season and returns to Newcastle on Saturday for a screening and book-signing at the Tyneside Cinema.

His first viewing of Zulu came on the 1972 re-issue. He admits to dragging his parents back twice more to see it after that initial outing. At school, it was the subject of an essay on My Favourite Film.

"I certainly remember gazing with eager anticipation at the colour lobby cards in the display case outside the cinema, and afterwards waiting for the bus home in a state of considerable excitement after the awesome spectacle I'd just seen," he says.

"What impressed me then was not just the impossibly heroic real life saga at its core - thought that in itself was surely enough to stir the schoolboy imagination - but the air of gravitas the film achieved, and its palpable respect for the 'enemy', which placed it above so many of the comic strip adventure movies I'd already seen."

Despite being a lifelong fan, he'd never thought about writing a book about the film until he mentioned his interest at a Tomahawk Press event publicising one of their books. The publishers virtually commissioned a book on the spot.

"I'd written a more academic piece about it which I wasn't very happy with. The book was a way of making up and doing a better job," he says.

"The astonishing thing is there are no books that cover Zulu in any depth, although in the time I've been writing other things have been published, including chapters in three books."

What surprised him as he did his research was just how well regarded the film is and the influence it has had. "I knew it was a popular film but didn't really bank on the fact that everyone knows someone whose favourite film it is," he says. "And there are all these organisations that have come from it. Like the 1879 group which, although dedicated to the real battle, was inspired by the film."

The movie had its origins in a series of magazine articles called Stories Of Endurance that John Prebble was commissioned to write in the mid-1950s.

He wrote a screenplay at the instigation of American Cy Endfield, a film-maker who'd moved to England after being blacklisted during the 1950s McCarthy communist witchhunt.

He and actor Stanley Baker, a miner's son from the Rhondda Valley, formed a production company to make the film. They pitched the idea to dozens of potential backers, who dismissed it as uncommercial.

The turning point came when Baker, filming Sodom And Gomorrah in Italy, handed the script to producer Joseph E Levine, who'd had a big success with a dubbed Italian epic, Hercules. He took on the project more because of its marketable image than any artistic beliefs. "I haven't had time to read it, but I liked the idea," he told Baker.

The budget - under $2m - meant casting mostly unknowns and newcomers. The only star names in the cast were Baker and Jack Hawkins. Fifth billed with the words "and introducing" was Michael Caine, as the aristocratic Lieutenant Bromhead.

He'd gone up for the role of Cockney Hook, but was cast as an upper class Englishman. His flatmate Terence Stamp was also considered but turned down as too well-known.

Filming on the site of the real battle wasn't possible, so the film-makers decided to shoot in Royal Natal National Park some 160 kilometres away.

As Hall's book details, filming in South Africa was restricted by the country's segregation laws. Zulus employed as extras were barred by race laws from staying in hotels with the other cast and crew, causing the film-makers to build them a special village compound live in.

For most of the shoot only 240 Zulus were employed, possibly a political decision as police considered a greater number would have represented a dangerous gathering.

Company members were contractually bound to obey the country's race laws, bringing home the realities of apartheid. At that time, there was no official opposition to working in South Africa, where the economic and practical advantages of filming made it ideal for Zulu.

Cast and crew could work with the Zulus but not befriend them in any way. "We couldn't offer them cigarettes, put an arm around a shoulder, sit and chat with them through an interpreter," recalls one of the production team.

There were rumours of plainclothes policeman on set and even spies planted among the crew to ensure rules weren't broken. Not everyone stuck to the regulations. One actor recalls how several of them crept down to the Zulu compound to drink the local beer and smoke a little "dagga" (marijuana).

Endfield had the task of explaining to the Zulus exactly what a film was as they'd never seen one before. A projector was hired to show them movies for the first time and explain the niceties of an historical reconstruction like Zulu.

Reviews for the film were mixed, but that didn't stop Zulu becoming a major hit, breaking box-office records.

Many of the major participants, including Baker and Endfield, are dead but Hall tracked down and spoke to many of the surviving cast and technicians. A month before the book was going to print, he discovered important papers relating to matters such as budgets and production schedules in the Academy of Motion Pictures Arts and Sciences' research centre in Los Angeles.

His thoroughness leads him to discuss the myths that have built up around the film, including the common one that Zulu extras were paid in wristwatches and can be seen wearing them on screen.

Not true, says Hall. They were paid government-approved wages of £4 a week. Perhaps, he suggests, the warriors' decorative wrist bracelets were mistaken for watches. No-one, to his knowledge, has ever cited an example of this apparent gaffe - and he challenges anyone to do so.

Since that first screening, Hall reckons he must have seen the film all the way through about 20 times, as well as certain scenes dozens and dozens of times. And, of course, he's watched it countless times on video and DVD (on which he provides a commentary).

His enthusiasm for Zulu hasn't dimmed although, after the current spate of screenings, he might give it a rest for a while. "I probably won't want to watch it again for some time - although it's still a thrill to see it on the big screen," he says.

* Sheldon Hall will introduce a rare big screen showing of Zulu (PG) at Newcastle Tyneside cinema on Saturday at 1.30pm. He will also be signing copies of his book Zulu - With Some Guts Behind It (Tomahawk, £25).