Nancy Reagan, the devoted wife and trusted confidante to late president Ronald Reagan who after his death became the most ardent guardian of his political legacy, died Sunday. She was 94.

The former first lady passed away at her home in Los Angeles from congestive heart failure, her spokeswoman Joanne Drake said.

She will be buried next to her husband at the Ronald Reagan Presidential Library in Simi Valley, California, Drake said.

Late in her life, Reagan earned praise for many of the very qualities that saw her savaged by critics during Ronald Reagan‘s two White House terms from 1981-1989 -- her fierce protectiveness and outsized influence on the president.

Perceived as regal and cold, she was feared by White House aides who often found themselves butting heads with her over policy and personnel appointments.

She made her own mark as first lady with her signature “Just Say No” drug awareness campaign launched in 1982.

But after leaving the White House, as she nursed Reagan through his descent into Alzheimer’s disease until his death in 2004, America softened its view of the former movie starlet.

Warm tributes noting Nancy Reagan‘s steadfast dedication to her husband poured in as news of her death broke.

“Nancy Reagan was totally devoted to President Reagan, and we take comfort that they will be reunited once more,” former first lady Barbara Bush said in a statement. “George and I send our prayers and condolences to her family.”

Added former California governor Arnold Schwarzenegger: “Nancy Reagan was one of my heroes. She served as first lady with unbelievable power, class and grace and left her mark on the world. She’s with her Ronnie now, but those of us she left behind will miss her dearly.”

Throughout her husband‘s illness, Nancy Reagan emerged as the epitome of a loving wife, as well as one of the country’s best-known advocates for stem cell research that might have saved her husband had a breakthrough been found in time.

President Reagan is viewed as something of a patron saint of conservatives and the patriarch of the modern Republican Party.

The diminutive former first lady wielded considerable political power, as a succession of Republican presidential hopefuls sought her endorsement over the years.

Born Nancy Davis in New York on July 6, 1921, she was the daughter of an actress and a car salesman who abandoned the family soon after she was born.

Her mother eventually remarried to a neurosurgeon.

In 1949, she went to Hollywood where she acted in B-movies and met her future husband.

They married in 1952 after Reagan divorced his first wife, actress Jane Wyman, beginning a marriage that has been described as a love story to rival any that the couple acted out on the silver screen.

The pair, who wrote passionate love letters to each other over the decades, had two children: Patti, born in 1952 and Ron, born in 1958.

When Reagan went into California politics in the 1960s, Nancy recast herself as the ultimate political wife and confidante, serving as his first lady there from 1967-1975.

Only months after he took office as U.S. president in 1981, Reagan narrowly survived an assassination attempt that spurred Nancy to take a keener role as her husband‘s protector, strictly controlling access to the president.

She sometimes set out to influence decision-making indirectly by taking her case to people her husband trusted. Other times, her role took on a bizarre twist as she consulted astrologers to guide administration policy.

“When she gets her hackles up, she can be a dragon,” former Reagan chief of staff Howard Baker said. Baker got his job after Nancy Reagan engineered the firing of his predecessor, Don Regan.

In a 1988 interview, Nancy Reagan said she was forced to exert her influence because her husband was poorly served by his aides, especially during the Iran-Contra scandal that tarnished his reputation.

To the public, Nancy Reagan became best known for her glamorous designer clothes, Hollywood friends and reported social climbing, as well as her “Just Say No” antidrug campaign.

Behind closed doors, her actions were much more important.

“Nancy wasn’t popular and she operated under cover, usually through a surrogate,” columnist Eleanor Clift wrote years ago in the Washington Post.

Clift said Nancy‘s “instinct for moderation drew her into debates over everything from social policy to U.S.-Soviet relations” as she tried to protect her husband from right-wing influence.

After the Reagans left the White House in 1989, “tell-all” books by Regan and especially an unauthorized biography by Kitty Kelley, cast Nancy Reagan in an unflattering light, even alleging an affair with Frank Sinatra.

But in 1994 she played a key role in her husband’s widely praised disclosure that he had Alzheimer‘s and became a vocal campaigner for awareness of the disease.

As his memory faded and he no longer recognized the woman he had loved for half a century, Nancy Reagan again closed ranks around him, shielding him from public view and even from old friends to protect his image and dignity.

“Ronnie’s long journey has finally taken him to a distant place where I can no longer reach him,” a rueful Nancy Reagan said at an Alzheimer‘s fund-raiser years ago. (AFP)