NEW YORK – For the past six years, Elaine Tettemer Marshall, the fourth-richest woman in the United States, has avoided the spotlight that ordinarily accompanies great wealth.

The 70-year-old Dallas resident controls almost 15 percent of Koch Industries, the second-largest closely held company in the U.S. Her stake in the industrial conglomerate, which generates annual sales of $110 billion, is worth more than $12.7 billion, according to the Bloomberg Billionaires Index, which has expanded to 100 names.

The only American women richer are Wal-Mart Stores heiresses Alice and Christy Walton and candy scion Jacqueline Mars.

Marshall, who gained control of the Koch stake after the death of her husband, E. Pierce Marshall, in 2006, has never appeared on an international wealth ranking, although her estate has been at the center of two Supreme Court cases involving her mother-in-law, Anna Nicole Smith.

“The Marshalls have never been a lightning rod because they’ve never been in the public view financially,” said Richard Lieb, a research professor of bankruptcy law at St. John’s University School of Law in New York, who filed briefs to the Supreme Court with his students when the cases were being heard.

“No one went after them to find out what their evil deeds were, if any.”

Marshall’s ability to stay out of the limelight stands in contrast to her father-in-law, J. Howard Marshall II, who had been a Koch shareholder for more than two decades and created a spectacle with his 1994 marriage to Smith, then a 26-year-old Playboy model, whom he wed at 89.

Since then, the Marshall fortune has been in a near-constant state of turmoil.

In April 1995, four months before J. Howard Marshall II’s death, Smith sued his son, Pierce, in Harris County, Texas, probate court, accusing him of interfering with his father’s ability to provide her spousal support.

The lawsuit was the first in a stream of legal cases that led to a 16-year battle between Smith and Pierce Marshall, the end of which neither would live to see. Marshall succumbed to an infection in 2006 at 67; Smith died of a drug overdose at 39 in a Florida hotel in 2007.

Fending off brothers

The partnership between the Koch and Marshall families began in 1959, when Koch Industries founder Fred Koch acquired a 35 percent stake in Great Northern Oil, a Minnesota refinery co-founded by J. Howard Marshall II, for about $5 million in cash.

A decade later, Koch’s second oldest son, Charles, offered to swap the rest of Marshall’s stake in Great Northern for Koch Industries shares.

“He took stock rather than cash – and held onto it,” said Robert L. Bradley Jr., editor of J. Howard Marshall II’s autobiography, “Done in Oil,” in an email. “The stock appreciated into something very, very large.”

In 1974, at the wedding reception of his oldest son, J. Howard Marshall III, the elder Marshall gave each of his two sons 4 percent of Koch Industries voting stock, telling them, “Boys, these are the crown jewels, take care of them,” according to documents filed by the U.S. District Court for California’s Central District in Santa Ana in 2002.

Those jewels played a crucial role in an attempted boardroom coup six years later, when two of Charles Koch’s brothers tried to oust him as CEO. With some cousins and several allies, Bill Koch and Frederick Koch controlled about 48 percent of the votes, and they turned to J. Howard Marshall II’s sons to gain the majority needed to displace Charles.

Howard III sided with the dissident brothers; his younger brother, Pierce, rejected their plea.

His loyalty tied to Charles Koch, J. Howard Marshall II thwarted the coup by buying back his oldest son’s voting stock for $8 million. According to court documents, Marshall subsequently disinherited Howard III, considering the $8 million payment “an early inheritance.”

Howard III contested his father’s will in Harris County probate court in 1995. But Pierce Marshall, who was left in charge of his father’s estate after his death, countersued, claiming his older brother committed fraud when he sold his Koch Industries voting stock back to their father at an inflated price.

The court sided with the estate. According to the verdict, rendered in 2001, Howard III had engaged in fraud by stating a claim to his father’s inheritance, and he was ordered to pay about $11 million to various Marshall family trusts. He and his wife, Ilene, filed for bankruptcy in Los Angeles in 2002.

Fending off stripper

While dueling with his brother, Pierce Marshall was also fending off charges from Anna Nicole Smith, who filed for bankruptcy in 1996.

During the bankruptcy proceedings, the former stripper, whose given name was Vickie Lynn Hogan, claimed her late husband had intended to set up a trust in her benefit. The trust was to have contained a sum equal to half of the increased value of Marshall’s assets during their marriage.

Pierce Marshall, Smith claimed, illegally interfered with the trust’s creation.

In 2000, the U.S. bankruptcy court for California’s Central District in Los Angeles awarded Smith about $475 million in damages, determining that Pierce Marshall had “deprived her of her expectancy of a substantial inter vivos gift from her deceased husband.”

The court based the award on the testimony of Smith’s expert witness, who offered three valuation methods for Howard Marshall’s stake in Koch Industries. The court found that “the most appropriate measure” estimated the stake’s value had grown from $741 million at the time of Smith and Marshall’s marriage to more than $1.6 billion in 1999.

Pierce Marshall appealed the decision. This time, the court based its verdict on the book value gain of J. Howard Marshall II’s stake in Koch from 1994 to 1995, as recorded in credit approval presentations to Texas Commerce Bank. The stake was worth $780 million at the end of 1995, according to the court.

Smith never got a dollar. The Harris County probate court, where she had filed her first lawsuit against Pierce Marshall, ruled in 2001 that she had no valid claim to the estate.

In 2006, the U.S. Supreme Court heard arguments on Smith’s case on the issue of federal jurisdiction over probate matters. The court ruled in favor of the Smith estate and sent the case back to California’s Central District Court, which reaffirmed its earlier verdict in favor of Smith. But the 9th U.S. Circuit Court of Appeals overturned the District Court in 2010, as it had in 2004.

So five years after its first ruling, the Supreme Court again took up Smith’s case, this time on another jurisdiction question. In its decision, the court upheld the ruling from the 9th Circuit Court, which stated that the California-based bankruptcy court lacked the constitutional authority to award Smith a claim over the Texas-based Marshall estate.

Setting up his wife

After the first Supreme Court decision in 2006, Pierce Marshall transferred his Koch stake, held by a company called Trof Inc., into a grantor retained annuity trust, or GRAT, named Staurolite.

Marshall owned all of Trof, according to the 2002 District Court ruling. Trof held 14.6 percent of Koch Industries, according to a 2001 application to the Federal Communications Commission, which was submitted by a company in which a Koch subsidiary held an interest.

Pierce Marshall was listed as Staurolite’s grantor and Elaine as the trustee, according to the trust agreement. Pierce also created his will at that time, leaving the majority of his estate to Elaine and appointing her as the executrix.

In his will, Pierce Marshall directed that, upon his death, all of his interest in Staurolite be transferred to the EPM Marital Income Trust, of which Elaine Marshall is the trustee. He died six weeks after signing his will.

In a brief submitted to the Supreme Court in March 2009, Howard K. Stern, the executor of the Anna Nicole Smith estate, accused the late Pierce Marshall of moving the family’s most valuable asset, Koch Industries stock, outside of his estate.

Elaine Marshall responded in a court declaration that the creation of the will and GRAT was the result of “18 months of planning, reparation and drafting” and was “not caused by the Supreme Court’s decision” that granted jurisdiction to the District Court in 2006 over Smith’s claim.