BOOKS & AUTHORS : One Honeymoon, Two Romances for Haeger : Trip to Paris inspired historical novel based on love affair between King Henri II and his mistress.

Diane Haeger of Newport Beach got more than she bargained for on her 1984 honeymoon in Paris: the inspiration to write her first novel, a historical romance based on the long love affair between France’s 16th-Century King Henri II and his mistress, Diane de Poitiers.

Romantic Times praises Haeger’s novel, “Courtesan” (Pocket Books; $5.99 ), as “lush in characterization and rich in historical detail.” B. Dalton’s romance newsletter calls it “a powerful historical novel, richly textured and beautifully researched.”

The former public relations assistant is pleased with the reviews but says she didn’t conceive the book as a “romance novel.”

“I saw it differently when I started out,” said Haeger, 34. “My greatest inspiration, I guess, was (historical novelist) Irving Stone. I loved the way he brought real stories to life. When I found this story, I was just really attracted to that. I just wanted to bring this story to life in the same way--and accurate way--that he used to do in his books.”

Haeger, who is under contract to Pocket Books for two more historical romance novels, said she is amazed at having a new career as a writer.

Although she had written short stories and several full-length novels in junior high school and high school “just to do it,” she had never submitted anything for publication. “I never thought I could make a career as a novelist. Everyone tells you it is impossible,” she said.

When she started writing “Courtesan” in 1985, Haeger was working on a Ph.D. in psychology. But her husband, Ken, a consultant to an international construction firm, encouraged her take a year off and “follow your heart.”

Before her Paris honeymoon, Haeger said, “I had read a little article in a magazine about this story so when we were there we went to some of the more famous castles that Henri and Diane had lived in. It seemed to me I was just confronted everywhere with evidence of their love.”

The king, she said, had even created a crest with his and Diane’s initials intertwined.

“You can still see it all over France today in tile work and in furniture,” she said. “He pretty much had it done on everything he could. It was in his own clothing, in the livery of his guards and servants and on all the cannons that went into battle. Which makes it interesting since she wasn’t his wife.”

In fact, during much of his relationship with Diane, Henri was married to Catherine de Medici. He had been forced into a political marriage with a woman he had never met, said Haeger, adding that Catherine knew about her husband’s mistress and, in fact, “they frequently all lived together in the same castle. Not happily, I’d say, but they did.”

Haeger said the term courtesan when applied to Diane de Poitiers, a widowed noblewoman, is something of a misnomer.

“The book tries to prove she was not a courtesan, which history has pretty much portrayed her as and which I take as a fairly negative term.” As Haeger sees it, a courtesan, “is a much more calculated woman” than Diane was.

In writing her novel, Haeger said, she wanted to show Diane “as Henri’s lover, partner, friend and basically his guide. He was thrust into his role as king with absolutely no warning (at age 29) and no training (because his older brother died). Her guidance made him what he was in his brief time as king.”

After 25 years together, their relationship came to a tragic end when Henri was in his 40s and he died after being wounded in a jousting match.

“It was actually rather gruesome,” Haeger said. “He caught a lance in his eye and lived for several days before he died. It was not a great way to go. They do claim--and it is sort of referred to in the book--that Nostradamus--a contemporary of his--predicted the death and tried to warn the king.”

But, alas, “he was a very Catholic king and believing prophesy went against his religious beliefs.”

In choosing to write about Henri and Diane, Haeger said, she was attracted to “the beauty of the love story. It also touched me because it was considered scandalous at the time because she was 16 years older than he was.”

Indeed, Haeger said, Diane was 31 when they began their affair, and Henri was “a young adolescent.” Actually, he was about 14 years old--a fact Haeger intentionally kept vague in her novel, lest it “take away from the story.”

“Age differences were different then than today,” she said. “Readers might take it as being almost strange if I actually went out there and said she was X years old and he was X years old. She was a widow with two children who were approximately his age. I think that’s scandalous in any time in history when your kids are the same age as your lover.”

Haeger, whose research included two return trips to Paris where she read Henri’s love letters and other correspondence in their original French, believes that “a relationship that begins when one of the people is in their adolescence and is strong enough--and deep enough--to carry on for 25 years is a pretty noteworthy relationship.

“I’d say it was a very intense, very enduring relationship that was probably beneficial on many levels to both of them. They were in different stages of their life, but they offered each other something they weren’t getting anywhere else, and I think that’s why they managed to stay together until his death.”

Under her contract with Pocket Books, Haeger already has completed her second novel, which is set in 19th-Century India and England; it’s due out next November. She’s now at work on the third book, which is set in China in the 1870s.

Meanwhile, Haeger is enjoying her debut as a novelist.

She says she’s surprised at the favorable reviews “Courtesan” has been receiving and says that, according to her publisher, orders from the chain bookstores “have been really strong.”

“As a new writer,” she said, “that’s the most fabulous thing you can hear.”