Former First Lady and family matriarch Barbara Bush was once described as 'a silver-haired pearl draped howitzer'.

But a combination of blows in her life in the mid-seventies sent her spiraling into a depression that almost led to her taking her own life.

Among the causes of her despair was a woman who would stay by her husband George's side for more than 12 years.

Her name was Jennifer Fitzgerald and she was his aide – and according to some, his mistress, reveals Susan Page, author of The Matriarch: Barbara Bush and the Making of an American Dynasty out next Tuesday.

Returning from a post in Beijing, China as chief of the US Liaison Office under President Gerald Ford, Barbara recalled the dizzying year as the best of times.

But it quickly evolved into the worst.

When Bush was assigned to head the embattled CIA in 1975, Barbara 'fell into darkness'.

Barbara Bush confessed she once fell into a serious depression and contemplated suicide, as friends close to the former First Lady speculate that her suicidal depression was aided by her husband George Bush carrying on a decade-long affair with aide Jennifer Fitzgerald. Pictured: Barbara Bush sitting behind George and Fitzgerald in 1975

Barbara (pictured with George in 1987), who died last April aged 92, said: 'I felt terrible. I would pull over and park so I wouldn't go hit a tree. I really wasn't brave enough to do that, but that's why I pulled over, so I wouldn't do that, or I wouldn't run into another car'

'Barbara Bush found herself falling into the worst personal crisis she had faced since daughter Robin had died more than two decades earlier,' writes Page. 'Overwhelmed by pain and loneliness, she contemplated suicide.

'She would pull over to the side of the road until the impulse to plow into a tree or drive into the path of an oncoming car had passed'.

'I felt terrible. I would pull over and park so I wouldn't go hit a tree', Barbara confessed to author Susan Page before her death.

'I really wasn't brave enough to do that, but that's why I pulled over, so I wouldn't do that, or I wouldn't run into another car'.

George held his weeping wife in his arms every night, while she tried to explain her feelings.

'I almost wonder why he didn't leave me', Barbara confessed to the author.

She was able to hide her depression from other family members and friends – but not George who encouraged her to get professional help.

When the crisis passed, Barbara theorized her depression was 'a toxic combination of factors'.

With George's new position at the CIA, it was the first time since his early days as chairman of the Harris County Republican Committee in Houston that he couldn't share with Barbara what he was doing. His job at the CIA was top secret.

'The truth is, I can't keep a secret', Barbara told the author in many conversations they had before Barbara's death in April of 2018.

'You tell me a secret, I'll keep it for about a day, maybe a day and a half'.

Barbara considered that with the onset of menopause, a hormonal imbalance might have set her off emotionally.

Or the empty nest at home with her children away at boarding schools or in new careers left her feeling inadequate to bring on such darkness.

But others who were close to Barbara speculated that there was an unmentioned reason that contributed to her grief and suicidal depression – Jennifer Fitzgerald.

A member of Bush's inner circle said when Bush was first introduced to Fitzgerald by Dean Burch in the 1970s, he 'was simply captivated'. Pictured: Fitzgerald in 1991

The two's flirtation supposedly began in 1973 when Bush was Chairman of the Republican National Committee. A woman sharing a beach house in Ocean City, Maryland, with Fitzgerald (left in 1990 and right in 1988), remembered Bush calling the house a least once a day during that summer

Respected White House correspondent, Ann Devroy wrote a story for Gannet News Service headlined 'The Power Behind Bush' illuminating Fitzgerald's 'almost unlimited influence' with Bush. Pictured: Barbara Bush sitting behind George and Fitzgerald in 1975

TIMELINE OF BUSH'S DECADE-LONG AFFAIR WITH JENNIFER FITZGERALD Early 1970s -- Bush is introduced to Jennifer by a mutual friend. They have flirtatious calls that lead to a romance that carries on for at least 12 years. 1974 -- President Gerald Ford appoints Bush to Chief of the Liaison Office in China. Barbara goes to Beijing with Bush but when she learns Jennifer - who has no foreign policy experience - is coming to China, she leaves. Barbara abruptly leaves China, hitching a ride home on the plane of Henry Kissinger, who happens to be visiting. For the first time the Bushes don't spend Christmas together. This period is described as a 'time of crisis' for the couple. Bush's mother comes to China to talk to her son, perhaps to act as an intermediary. 1975 -- Bush is appointed director of the CIA. Jennifer is brought in as an aide. Barbara is said to have considered suicide and was in a serious depression. Friends speculate Jennifer was one of the factors to this. 1980 -- Bush decides to run for president, going up against Ronald Reagan - later becoming his VP. His campaign manager and best friend, Jim Baker, gives Bush an ultimatum to decide between him and Jennifer. Baker is shocked when Bush says he would need to think about it. Ultimately he moves Jennifer to another job. 1981 -- Bush is Vice President and brings Jennifer back to his staff again. Reporters claim she has 'almost unlimited influence' with Bush. Barbara even brings up the Jennifer problem to her husband. He tells her 'she is just what he wants, and the hell with it all.' 1988 -- Bush runs for president, successfully this time. The Jennifer problem comes up again. Several Bush aides doubt Bush's story about his relationship with Jennifer but decide if Barbara can put up with it, then they can. Advertisement

Fitzgerald, small and blond, was seven years younger than Barbara.

She was divorced and very protective of George while being 'prickly to others'.

Speaking on the condition of anonymity, a member of Bush's inner circle told Page that when Bush was first introduced to Fitzgerald by Dean Burch in the 1970s, he 'was simply captivated'.

'Just seven years younger than Barbara and not a striking beauty, she was flirty and solicitous and focused completely on him.

'Their surreptitious romance would last for more than a dozen years, inexplicable to those around him and impossible for anyone to manage', writes the author.

Their flirtation supposedly began in 1973 when Bush was Chairman of the Republican National Committee.

A woman sharing a beach house in Ocean City, Maryland, with Fitzgerald, remembered Bush calling the house a least once a day during the summer of 1973.

'Her giggly manner and their whispered conversations made it so clear that the calls were personal', writes the author.

Bush didn't even bother to use a phony name.

He initially hired her as his assistant when he accepted the post in China in 1974.

The move reportedly led Barbara to leave Beijing for the U.S. for a short period of time after learning that Fitzgerald was hired.

She hitched a ride home with Secretary of State Henry Kissinger who had been making a diplomatic visit with his family.

Although Barbara would claim the trip had been planned for months, George's mother came to stay for three weeks.

Finally, Barbara returned back to China until January 1975 - marking the first Christmas the couple had ever spent apart and the longest time they went without seeing each other during their marriage.

During the 1980 campaign when Bush was nominated for Vice President and working out of his Houston headquarters, his suspicious campaign manager and best friend Jim Baker gave Bush an ultimatum to decide between him and Jennifer.

Bush took a day to mull it over, much to Baker's shock, but eventually moved Fitzgerald to a fundraising position in New York.

When Bush was elected Vice President, he brought her along to Washington and she sat outside his office door in the White House as his gatekeeper.

Rumors about Bush and other women had circulated in Washington for years, with a bizarre allegation in 1981 that Bush had been shot leaving the Capitol Hill home of a woman in the early morning hours, but it was never substantiated.

The Washington Post covered it anyway in a front-page story.

But the whispers about Fitzgerald never ceased.

Respected White House correspondent, Ann Devroy wrote a story for Gannet News Service headlined 'The Power Behind Bush' illuminating Fitzgerald's 'almost unlimited influence' with Bush.

Devroy wrote about when key campaign staffer Rich Bond confronted Bush and declaring he just couldn't work with Fitzgerald anymore. He soon got the boot.

Barbara said her suicidal depression came about a year after she returned from a post in Beijing where George was serving as chief of the US Liaison Office in 1975 under President Gerald Ford. Pictured: The couple in Beijing in 1974

Only when Bush won the Presidency in 1988 (pictured) did he agree to move Fitzgerald off his staff but he made her deputy chief of protocol at the State Department

'I was very close to her for a while. And liked her', George Bush told historian Jon Meacham. 'I knew she was difficult, and knew other people didn't like her. She was hard to work with for other people around her'. When asked if they had an affair, he responded with a simple 'no'. George and Barbara are pictured in 1978

Time Magazine also covered Fitzgerald's questionable status with Bush.

By 1992, Fitzgerald was still close by George's side and a biography of a Washington lobbyist included a very suggestive event dating to 1984: 'A US ambassador had complained about being asked to arrange for Bush and Jennifer Fitzgerald to share a private cottage during an official visit to Geneva', according to the biography.

The ambassador died in 1986 but not before telling friends, 'It was obvious that the pair were romantically involved', writes Page.

Old Texas friends of Bush told the author that the stories were 'bullsh*t'.

Several aides chose to leave rather than have to work with her and ceaseless rumors humiliated Barbara, as well as fueling politically perilous gossip.

Bush was never willing to dismiss her and when making his 1988 presidential bid, she ran his Senate office – still his aide.

Only when Bush won the Presidency in 1988 did he agree to move her off his staff but he made her deputy chief of protocol at the State Department.

The Washington Post wrote that Fitzgerald 'has served president-elect George Bush in a variety of positions'.

'I was very close to her for a while. And liked her', George Bush told historian Jon Meacham.

'I knew she was difficult, and knew other people didn't like her. She was hard to work with for other people around her'.

When asked if they had an affair, he responded with a simple 'no'.

'I used to think she was terrible', Barbara confessed to Bush's executive assistant, Chase Untermeyer. 'Now I just feel sorry for her'. Pictured: Barbara and George in 2017

'I used to think she was terrible', Barbara confessed to Bush's executive assistant, Chase Untermeyer. 'Now I just feel sorry for her'.

But Barbara wrote in her diary after the affair was first speculated by the press, 'My own opinion is that Jennifer really does hurt George'.

'His eyes really glaze over when you mention her name. She is just what he wants, he says and says the hell with it all'.

Jennifer made news again in 1990 when she was fined $648 for failing to report to customs that she was bringing into the States a silver fox fur cape and fur-lined raincoat she had purchased in Argentina.

Retired and living now in Florida, she continues to deny any affair. 'It simply didn't happen', she told Page.

'I have nothing but the deepest respect and admiration for the entire Bush family'.

Bush would continue to deny their affair until the day he died last November.

The Matriarch: Barbara Bush and the Making of an American Dynasty by Susan Page is available on Amazon next Tuesday.