Nelson Mandela once said his wife, Graca Machel, makes him "bloom like a flower." Despite her reluctance to marry him at first, they've been inseparable since they tied the knot on his 80th birthday.

Here are 10 things to know about the woman who was at the international icon's side to the very end.

She's been first lady of two nations: Before she got married to the South African anti-apartheid icon, Machel was the first lady of Mozambique. Her husband, President Samora Machel, died in a mysterious plane crash in 1986.

She was much younger: When they got married in 1998, she was 52. But she says their advanced age made their relationship better. "We were grown up; we were settled; we knew the value of a companion, of a partner," she says.

She separated the man from the icon: At the beginning of their relationship, Machel says, there was a conflict between the man she married and the world's perception of him. "The aura around him was a bit confusing. But then I learned to live with it, in terms of separating the two," she told CNN's Robyn Curnow in a rare interview in 2008.

South Africa wasn't always in love with her: Protective of their beloved Madiba, the nation did not warm up to a foreign first lady at first. She remained in the background at the beginning, and then slowly won them over with her loyalty and laid-back demeanor.

She has something in common with the Kennedys: In Mozambique, she was nicknamed Jackie Kennedy. Not just for her class and grace, but because of the tragedy that befell her husband while in office.

It wasn't love at first sight: After they met, she was reluctant to marry him or discuss their relationship in public. But Mandela wooed her the old-fashioned way, occasionally giving his bodyguards headaches as president when he'd make unannounced stops to buy her chocolates.

She's kindred spirits with Mandela: Machel has something in common with her freedom fighter husband. While living in Mozambique, she was outspoken against the Portuguese colonial government.

She's qualified in her own right: She served as minister of education and culture in Mozambique for more than 10 years. She is especially passionate about youth education, and has served as an expert on children's issues for the United Nations.

She's Mandela's third wife: Mandela was first married to Evelyn Mase, but their marriage ended in divorce. In his biography "Long Walk to Freedom," Mandela has said Mase made him choose between family and politics. He later married Winnie Mandela, a firebrand who became his voice when he was in prison. After their contentious divorce in 1996, Mandela married Machel two years later.

Their wedding was private: Despite Mandela's larger-than-life status, they got married on his birthday 15 years ago. Their wedding was a low-key event attended by close family and friends.

Nelson Mandela: Surprising facts you probably didn't know

He was loved and admired the world over, profiled in books and movies, and showered with awards and accolades. But even the most public of personalities have little-known facts buried in their biographies.

Here are 10 surprising facts you probably didn't know about Nelson Mandela:

1. He lived up to his name: Mandela's birth name was Rolihlahla. In his Xhosa tribe, the name means pulling the branch of a tree or troublemaker. (The name "Nelson" was given to him by his teacher on his first day of elementary school. It's not clear why she chose that particular name. It was the 1920s, and African children were given English names so colonial masters could pronounce them easily).

2. He had a cameo in a Spike Lee film: He had a big part in Spike Lee's 1992 biopic "Malcolm X." At the very end of the movie, he plays a teacher reciting Malcolm X's famous speech to a room full of Soweto school kids. But the pacifist Mandela wouldn't say "by any means necessary." So Lee cut back to footage of Malcolm X to close out the film.

3. There's a woodpecker named after him: From Cape Town to California, streets named after Mandela abound. But he's also been the subject of some rather unusual tributes. Last year, scientists named a prehistoric woodpecker after him: Australopicus nelsonmandelai. In 1973, the physics institute at Leeds University named a nuclear particle the 'Mandela particle.'

4. He married a first lady: Before tying the knot with Mandela on his 80th birthday, Graca Machel was married to Mozambique President Samora Machel. Her marriage to Mandela after her husband's death means she has been the first lady of two nations.

5. He was a master of disguise: When Mandela was eluding authorities during his fight against apartheid, he disguised himself in various ways, including as a chauffeur. The press nicknamed him "the Black Pimpernel" because of his police evasion tactics. "I became a creature of the night. I would keep to my hideout during the day, and would emerge to do my work when it became dark," he says in his biography, "Long Walk to Freedom."

6. A bloody sport intrigued him: Besides politics, Mandela's other passion was boxing. "I did not like the violence of boxing. I was more interested in the science of it - how you move your body to protect yourself, how you use a plan to attack and retreat, and how you pace yourself through a fight," he says in his biography.

7. His favorite dish is probably not yours: He's been wined and dined by world leaders. But what Mandela loved eating most was tripe. Yup, the stomach lining of farm animals.

8. He quit his day job: He studied law at the University of Witwatersrand in Johannesburg and opened the nation's first black law firm in the city in 1952.

9. He was on the U.S. terror watch list: Mandela wasn't removed from the U.S. terror watch list until 2008 -- at age 89. He and other members of the African National Congress were placed on it because of their militant fight against apartheid.

10. He drew his inspiration from a poem: While he was in prison, Mandela would read William Ernest Henley's "Invictus" to fellow prisoners. The poem, about never giving up, resonated with Mandela for its lines "I am the master of my fate. I am the captain of my soul." You may know it from the movie by the same name starring Morgan Freeman as Mandela.