am choosing to write this book to my sons," John Steinbeck wrote. The year was 1951, and the Pulitzer Prize-winning author was drafting a letter about the manuscript that would become "East of Eden," his epic story about family and betrayal.

"They are little boys now and they will never know what they came from through me, unless I tell them," Steinbeck wrote to Pascal Covici, his longtime friend and editor. "It is not written for them to read now but when they are grown and the pains and joys have tousled them a little."

In the 53 years since, life has indeed tousled the Steinbeck clan. Since John Steinbeck's death in 1968, his heirs have clashed over control of his literary estate and accused one another of betrayal, earning the family some renown in literary and legal circles. The fighting has left the family bitterly divided, in an epic entanglement that draws inevitable snickers that it could have been written by Steinbeck himself.

The latest chapter began last month when two heirs, Thomas Steinbeck and Blake Smyle, Steinbeck's son and granddaughter, sued the estate of his third wife, Elaine, and McIntosh & Otis, a New York literary agency that represented Steinbeck. Steinbeck, whose sons were born in his second marriage - to Gwyndolyn Conger - and Elaine, who had a daughter from a previous marriage, married in 1950 and had no children of their own. She died in April 2003 at 88.

In the complaint filed in United States District Court for the Southern District, in Manhattan, Mr. Steinbeck, known as Thom, and Ms. Smyle, the daughter of the writer's younger son, John Steinbeck IV, allege that Mrs. Steinbeck and the agents "engaged in a 30-year hidden conspiracy to deprive John Steinbeck's blood heirs of their rights in the intellectual properties of John Steinbeck." They seek damages of $10 million and $8 million, respectively. John IV, who wrote of his struggles with addiction, died during surgery for a herniated disk in 1991 at 44.

The roots of the Steinbecks' legal troubles reach back to the will Steinbeck wrote shortly before his death, in which he left most of his estate, valued at over $1 million, to Elaine. To his sons he left $50,000 each. (Steinbeck, renowned for writing about the working class, left a housekeeper $5,000.) He directed future profits from his works, including novels and screenplays, to go to his wife and a lawyer. His will said nothing of copyrights.

Under copyright law at the time of his death, children and spouses of writers had interests in the renewal of copyrights. In 1981, Steinbeck's sons sued Elaine as the executor of their father's estate, claiming that she had renewed some copyrights in their name, but kept the royalties. The suit was settled in 1983, and the terms of the settlement are sealed.

When she died last year, Elaine Steinbeck left her estate, including her copyrights of her late husband's works, to two sisters, her daughter and several grandchildren, none of whom are biologically related to the writer.

The current suit questions whether Mrs. Steinbeck, who it says was motivated by jealousy of her stepsons, properly exercised renewal rights for her late husband's works, and whether the heirs were properly informed of their interests in those rights. It claims she acted in violation of the 1983 agreement.

Thomas Steinbeck and Ms. Smyle declined to be interviewed, according to their lawyer, Mark S. Lee of Manatt, Phelps & Phillips in Los Angeles.

Employees at McIntosh & Otis did not return phone calls. John T. Williams, a lawyer and literary agent and co-editor of "Perle & Williams on Publishing Law," a two-volume encyclopedia of publishing law that includes a section on literary agencies, said the agency was highly regarded.

The defendants, who include a sister, a daughter and a granddaughter of Elaine Steinbeck, have until this week to file their responses or seek an extension.

"The whole story has a tragic arc to it," said Jonathan Zittrain, an assistant professor of intellectual property law at Harvard. "This isn't Disney versus Miramax. These are the heirs to arguably one of America's greatest writers" fighting over his legacy, he said.

While the suit involves copyright law, many of Mr. Steinbeck's and Ms. Smyle's allegations were factual in nature - "who did what when," Mr. Zittrain said.

According to the suit, Steinbeck was "an author or artist who cared little for business matters, including his intellectual property" and so he neglected to say how his copyrights should pass, a view not shared by all.

"I think he wanted to leave them enough so they wouldn't starve, but not so much so they wouldn't have to make lives for themselves," said Jackson J. Benson, who spent 13 years researching and writing "The True Adventures of John Steinbeck, Writer" (Viking Press 1984, Penguin Group 1990), considered by many the definitive biography of Steinbeck. "The main thing was he didn't want to screw up the boys' lives by leaving them all that money. Well, the irony is, the boys did go after it."

Material wealth, and a lack of it, contributed greatly to Steinbeck's vision as a writer. In stories, the Stanford University-educated writer returned again and again to characters shaped by economic deprivation, at times romanticizing them - like the well-intentioned ne'er-do-wells in "Tortilla Flat" and "Cannery Row" - and at others, laying bare their suffering - like that of the destitute Oklahomans displaced by the Dust Bowl in "The Grapes of Wrath" - and almost always revealing their dignity.

After his successes piled up, Steinbeck recalled his lean years in the 1920's in New York City, where he had worked briefly pushing a wheelbarrow on the construction site of Madison Square Garden, and in California.

"I had $25 a month and I was one of the rich ones," he wrote in 1955 in The New York Times about his life on Cannery Row in Monterey, Calif. "But it was far from as bad as it sounds. Hamburger was three pounds for a quarter, plate beef 5 cents a pound. For 15 cents you could pick out a bag of 'soup vegetables' that would feed you for a week And then we had the ocean to fall back on.

"In our group of denizens, we had no envy for the rich. We didn't know any rich. We thought everyone lived the way we lived, if we thought of it at all."

Once Steinbeck experienced financial success, he began worrying about future income, although "it does seem odd as we read through 'Journal of a Novel' to find a man who buys a piano on impulse also worrying about money," Mr. Benson wrote in his biography.

Steinbeck had little cause for concern. He won the Nobel Prize for literature in 1962, and even as wide critical acclaim eluded "East of Eden" in his lifetime, it generated strong sales and still does, like the other Steinbeck works that have become staples of the classroom.

Last year, on an episode of "The Oprah Winfrey Show" dedicated to the novel for Ms. Winfrey's book club, Thom Steinbeck, who published a collection of short stories in 2002, recalled reading "East of Eden" for a high school class and getting a D on his book report, much to his father's chagrin.

"It scared the pants off me," Mr. Steinbeck said of the book, with good and evil themes, that his father wrote to him and his brother. "I wondered whether he was talking about real demons or whether he was keeping the demons from the door."

He added: "Whether if by discussing these things and bringing them out, he could prevent what he feared might happen to his own family."