Ken Follett on the set of "World Without End" (2011 Tandem Productions GmbH )

Well before blockbuster movies, there were blockbuster novels: big, juicy, page-turning epics, with dozens of characters, exotic settings and multiple plots playing out over several years, often against the backdrop of some extended historical conflict. Tolstoy largely invented the form in 1869 with “War and Peace,” and by the middle of the 20th century, its latter-day stalwarts — including James Jones, Herman Wouk and the tireless fiction factory known as James Michener — bestrode the bestseller lists like the titans they were.

In recent years, however, the form has fallen somewhat out of favor with writers, if not with readers. Who wants to spend so much time, day in and day out, with the same set of protagonists? Who wants to do all that research? Who has the nerve, not to mention the patience, to keep all those narrative balls in the air over hundreds of pages?

Ken Follett, actually. At 63, the Welsh author is one of the last Mohicans of the form, having traded his highly successful thrillers (“Eye of the Needle,” “The Key to Rebecca”) for the multigenerational historical saga in 1989’s “The Pillars of the Earth” (adapted as a Starz miniseries in 2010) and its sequel, 2007’s “World Without End,” which premieres as a miniseries on Reelz next month.

Now Follett is amid his most audaciously ambitious project yet: the Century Trilogy, in which five interrelated families — American, Russian, German, English and Welsh — battle through the most dramatic events of the 20th century in a story that will sprawl over nearly 3,000 pages. The first volume, the bestselling “Fall of Giants” (2010), encompassed World War I, the Russian Revolution and the struggle for women’s suffrage. The second, a 940-page doorstop of a book called “Winter of the World” (Dutton, $36) — to be published Sept. 18 — takes on the rise of Nazi Germany, World War II, the dawn of the atomic age and the beginnings of the Cold War.

“Certainly it’s easier to write a 100,000-word thriller than it is to write one of these bigger novels, which are three times as long and 10 times as difficult,” Follett says in a phone interview from his home in London. “You have this group of characters and you write 100,000 words about them, but you haven’t finished; you have to keep making up more and more stuff about them. A regular novel is a snapshot of the major characters at some moment, probably some crisis, in their lives. In a novel like ‘The Pillars of the Earth,’ for example, you’ve got to tell their entire biographies, including conflicts and romances that can go on for 50 years or more. It’s damned hard, but readers adore it.”

This book cover image released by Dutton shows "Winter of the World," by Ken Follett. The book, the second of his "Century" trilogy on war, will be released on Sept. 18. (AP/AP)

So do publishers. “No one is really writing the kinds of stories he’s writing,” says his editor at Dutton, Leslie Gelbman. “Ken is a master storyteller, and he does it through his plots, great characters and his use of history, which really transports you to another time and place. Since Michener’s time, people maybe have wanted a different kind of book, but publishing is cyclical. Ken’s been bringing it back, and now we’re full circle again.”

In the Fleming mode

The tale of Follett’s literary career begins in irony. Growing up in Cardiff, Wales, as the eldest son of parents who were members of a fundamentalist Protestant sect known as the Plymouth Brethren, young Ken was forbidden to watch TV or movies or attend the theater. But his parents were curiously lax about his reading material. Ken was allowed to read anything he liked — which, as it happened, ran along the thriller line, with particular emphasis on the novels of Ian Fleming, featuring a certain British spy code-named 007.

“At the age of 12, when I started to read the James Bond stories, I was completely blown away, even though there was a great deal in the novels that I didn’t understand, such as the very strong streak of sexual sadism,” he recalls. “I remember asking my father what a martini was, and him saying, ‘Oh, some kind of drink.’ No one in my family had ever had a martini.” Follett laughs merrily. “Ten years later, when I started writing fiction myself, my touchstone was the James Bond stories, in that I wanted to give readers the same kind of excitement.”

After a few years as a newspaper reporter in Cardiff and, later, London, Follett went into publishing and began writing fiction as something of a lark. Several of his early novels — short, fast, a bit racy in the Fleming mode — were published under pen names.

“When I wrote my first novel [1974’s ‘The Big Needle’], my agent said I should publish it under a pseudonym,” Follett says. “When I asked why, it was clear to her, not to mention other people, that I hadn’t hit my stride. She told me, ‘One day you might want to write something better.’ ”

She was right. In 1978, Follett produced his first big hit, “Eye of the Needle” — made into a popular 1981 film starring Donald Sutherland as a conflicted German spy during World War II — and proceeded to write a series of taut thrillers, including “The Man From St. Petersburg” (1982), “On Wings of Eagles” (1983) and “Lie Down With Lions” (1986), each of them landing at or near the top of the bestseller lists. Follett grew rich and famous, with houses in several countries (currently including Antigua), and married Barbara Broer, a Labor Party operative who became a member of Parliament. (They share a country house in her old jurisdiction of Stevenage, England, with two Labradors, Bess and Caramel.)

By the mid-’80s, Follett wanted to try something new. “No matter how successful you are, there comes a time when you start to get bored, even though everybody wants you to write the same book over and over again,” he says. “It’s easy to succumb to that, but I felt there was a great popular novel to be written about the construction of a medieval cathedral, which, of course, takes place over a great many years and would necessarily be a much longer, more complicated story — very different from what I’d been doing. A lot of people advised against it; one of my publishers took Barbara aside and said, ‘You’ve got to stop Ken writing this book — it’s going to destroy his career.’ But I ended up reinventing myself with ‘The Pillars of the Earth,’ and it was the biggest book of my career. I didn’t plan it that way, but in hindsight I could tell myself, ‘That was a smart move, Follett.’ ”

Time is ripe for risk

Since “The Pillars of the Earth,” Follett has oscillated between big historical epics and shorter thrillers such as “The Third Twin” (1996), “The Hammer of Eden” (1998) and “Whiteout” (2004). In the Century Trilogy, he blends the modes. “When Ken told me he was planning to do the trilogy, I said, ‘Bingo,’ ” recalls his agent for 16 years, Amy Berkower. “To me, it takes the best of what Ken has done in the past, the ‘Eye of the Needle’-type story, and combines it with ‘The Pillars of the Earth’-type book, which is harder to do because you have to be a great storyteller at such a large scope. It’s the best of both worlds.”

Follett’s impulse to write the trilogy grew out “World Without End,” which was virtually as successful as “Pillars of the Earth.” “When I realized I was capable of writing books that would get a much more profound reaction from readers than my thrillers have done, I wanted to do it again,” he says. “I didn’t want to do another medieval story, though, and so I thought of the 20th century, the most dramatic century in the history of the human race — the greatest inventions, the worst wars, more people killed in war than in all the previous centuries put together. I thought the idea was terrific.”

But was he capable of pulling off such an audacious feat? “I was by no means sure,” he says. “But I figured that by that point, I had been an author for something like 30 years, and I really owed it to myself to take that risk. Of course, I’m past the age when you might cheerfully think to yourself, ‘I might do that in 15 years’ time.’ If I was going to do something that ambitious, there was really no other time to do it than now.”

Will the Century Trilogy follow its predecessors as a miniseries? “It’s going to be the most expensive miniseries in the history of television, and for that reason it will probably never get made,” Follett says. “I’m not going to let anybody do it cheaply, either. They’ve either got to bet the farm or not do it at all.”

Nance is a freelance writer.