"Then she came into the room, shining in her youth and tall striding beauty," Ernest Hemingway wrote of Renata, the heroine of his 1950 novel Across the River and into the Trees. "She had pale, almost olive-colored skin, a profile that could break your, or anyone else's heart, and her dark hair, of an alive texture, hung down over her shoulders."

For three decades Venice society has known that Hemingway modeled Renata after a real woman: She was Adriana Ivancich, the beautiful daughter of a local aristocrat. Her relationship with the author had begun when he was a whiskey-and-war-weary 49, she just shy of her 19th birthday. To spare Adriana's reputation, Hemingway forbade the publication of Across the River in Italy for 10 years. That was not enough to prevent a scandal, which she bore stoically, in Venice. Only now, 19 years after Hemingway's suicide, has Adriana come forth with her side of the story in a memoir. "I let the scandal freeze into oblivion and my sons grow up," she explains. "But I owe this book to Papa. This was a responsibility I had to face. I am the missing link in his life."

Adriana's strange relationship with Hemingway has proved enthralling to the irrepressibly romantic Italians. Her book, The White Tower, was published only last month and is already climbing the Italian best-seller lists. The book-jacket photograph of Adriana, shyly leaning against Hemingway's massive chest, is everywhere in Rome. "What happened when we met is a little more than a romance," says Adriana, now 50. "I broke down his defenses; he even stopped drinking when I asked him to. I'm proud to remember I led him to write The Old Man and the Sea." Casting herself as muse rather than model, she does not take credit for Across the River, which is often considered Hemingway's worst novel. "Yes, naturally he wrote it for me, thinking of me, but I didn't like the book and I told him so," Adriana says. "I always criticized him when I felt something was wrong, and he changed, and something in me changed too. I shall never stop being grateful to Papa for that."

He was on a hunting trip in northern Italy with a friend of her family when they met in 1948. Adriana was bedraggled from a sudden rainstorm. He broke his comb in two and gave her half. Hemingway was captivated by her long-necked, swanlike beauty, her obvious intelligence and her romantic history. Born into a socially prominent family, Adriana had divided her childhood between a Venetian palazzo and a 16th-century villa in the countryside. Raised by her mother, a severe disciplinarian, after her father died in the war, Adriana was particularly susceptible to the flattering attention of an older man. Hemingway entertained her on many long evenings at the Hotel Gritti Palace restaurant in Venice and in front of the fireplace at her family's country home. To encourage her interest in writing poetry and taking photographs, he gave her his old Royal typewriter and his Rolleiflex camera. He convinced his Italian publishers to hire Adriana, a talented artist, to illustrate the dust jackets of his books. For seven years, whenever they were separated, he sent her long, effusive letters. From Nairobi in 1954, after two plane crashes in two days left him with severe internal injuries, he wrote, "I love you more than the moon and the sky and for as long as I shall live. Daughter, how complicated can life become? The two times I died I had only one thought: 'I don't want to die, because I don't want Adriana to be sad.' I have never loved you as much as in the hour of my death."

In the semiautobiographical Across the River, a middle-aged colonel and young Renata make furtive love in a gondola. Adriana's reputation suffered because of the passage; in her hometown she was ostracized. Yet, as she tells it now, she and Hemingway never indulged in anything more than occasional kisses—which they decided were "mistakes." "Never," Adriana insists, "did he do the slightest thing that might oblige me to be defensive." (There is speculation that because of injuries, age and liquor, Hemingway was impotent at that point in his life.) Adriana claims that Hemingway did once ask her to marry him, although he already had a wife, Mary. "That's nonsense," says Mary Hemingway, now 76. "Ernest was fond of her, as he was fond of quite a few young women. He certainly didn't make this one a problem for me." In any case, Adriana says she never seriously considered the proposal. "He was too old," she explains. "He was married. It was unthinkable."

Perhaps Adriana's fondest memories of Papa are set in Cuba, where she and her mother visited him and Mary. During the day Hemingway would write at his desk at the bottom of a stone tower on the property, while Adriana labored over her drawings at the top. She recalls that once he scratched their wrists and dipped a pen in their blood, forming a "secret organization" he called "White Tower, Inc." (hence the title of her book). Every morning she would go down to visit him as he worked. "He thanked me," she remembers. "He said words flowed out from him easily thanks to me. I simply uncorked the bottle."

Adriana has been happily married for 17 years to a German count, Rudolph von Rex. She lives with him and their sons, Carlo, 14, and Nicola, 12, on a farm in Tuscany. The family palazzo still belongs to her brother, but he has rented it to a tourist organization. "Keeping a palazzo in Venice is an impossible task," she complains. "It is the general Venetian tragedy—pollution, foundations crumbling, walls falling to pieces. The only way to cope with all this is to have money and power."

Adriana's book will be published in the U.S. unless the Hemingway Foundation, which controls his estate, tries to block it on grounds that her excerpts of his letters constitute a copyright infringement. "Ernest left very specific instructions in his will that his letters be destroyed," says Mary Hemingway. "I would attempt to follow his wishes." Hemingway's heirs cannot complain that Adriana's memoir is sensationalist, however; her prose may be purple but the story is chaste.

She last saw Hemingway in Venice in 1955. They sat on the Gritti terrace overlooking the Grand Canal. It was sunset in one of the world's most beautiful cities. Adriana remembers that tears rolled down the author's cheeks. "Look, daughter," he said. "Now you can tell everyone you saw Ernest Hemingway cry."

Adriana was back in Venice earlier this month, having a drink with a friend on the same terrace. "Being a Venetian," Adriana said, with a distant smile, "is a psychological handicap. Nothing is ever good enough, and floating is one's favorite way of facing life."