JFK's sister and founder of the Special Olympics; Born July 10, 1921; Died August 11, 2009.

Eunice Kennedy Shriver, who has died aged 88 after suffering a series of strokes, was the sister of President John Kennedy who carried on the family's public service tradition by founding the Special Olympics and championing the rights of the mentally disabled.

As celebrity, social worker and activist, Shriver was credited with transforming America's view of the mentally disabled from institutionalised patients to friends, neighbours and athletes. Her efforts were inspired in part by the struggles of her mentally disabled sister, Rosemary.

Shriver was also the sister of assassinated Senator Robert F Kennedy and Senator Edward Kennedy, the wife of 1972 vice-presidential candidate and former US Peace Corps director R Sargent Shriver, and the mother-in-law of California governor Arnold Schwarzenegger. With Eunice Shriver's death, Jean Kennedy Smith becomes the last surviving child of Joseph and Rose Kennedy.

A 1960 Chicago Tribune profile of the women in then-candidate JFK's family said Shriver was "generally credited with being the most intellectual and politically minded of all the Kennedy women".

When her brother was in the White House, she pressed for efforts to help troubled young people and the mentally disabled. And in 1968, she started what would become the world's largest athletic competition for mentally disabled children and adults. Now, more than a million athletes in more than 160 countries participate in Special Olympics events each year.

In 1990, she came to Glasgow when it hosted the European games and was full of praise for the city and Strathclyde Regional Council's efforts. The UK version of the games was held in the city 15 years later.

"When the full judgment on the Kennedy legacy is made - including JFK's Peace Corps and Alliance for Progress, Robert Kennedy's passion for civil rights and Ted Kennedy's efforts on health care, work place reform and refugees - the changes wrought by Eunice Shriver may well be seen as the most consequential," Harrison Rainie, author of Growing Up Kennedy, wrote in 1993.

It was Shriver who revealed the condition of her sister Rosemary to the nation in a newspaper article during her brother's presidency. Rosemary Kennedy underwent a disastrous lobotomy when she was 23, though that was not mentioned in the article. She lived most of her life in an institution in Wisconsin and died in 2005 aged 86.

The roots of the Special Olympics go back to a summer camp Shriver ran in Maryland in 1963. Realising the children were far more capable of sports than experts said, Shriver organised the first Special Olympics in 1968 in Chicago. The two-day event drew more than 1000 participants from 26 states and Canada.

By 2003, the Special Olympics World Summer Games, held that year in Dublin, involved more than 6500 athletes from 150 countries. The games are held every four years. Well into her 70s, Shriver remained a daily presence at the Special Olympics headquarters in Washington.

Eunice Shriver was the recipient of numerous honours, including the nation's highest civilian award, the Presidential Medal of Freedom, which she received in 1984. In May, the US National Portrait Gallery installed a painting of her - the first portrait commissioned by the museum of someone who had not been a president or first lady.

She was born in Brookline, Massachusetts, the fifth of nine children to Joseph P Kennedy and Rose Fitzgerald Kennedy. She earned a sociology degree from Stanford University in 1943 after graduating from a British boarding school while her father served as ambassador to Great Britain.

She was a social worker at a women's prison and worked with the juvenile court in Chicago in the 1950s before taking over the Joseph P Kennedy Foundation with the goal of improving the treatment of the mentally disabled. The foundation was named for her oldest brother, Joseph Jr, who was killed in the Second World War.

In 1953, she married Sargent Shriver. He became JFK's first director of the Peace Corps, was George McGovern's vice-presidential running mate in 1972, and ran for president himself briefly in 1976.

Survivors include her husband, who was diagnosed with Alzheimer's disease in 2003, and the couple's five children: former NBC newswoman Maria Shriver, who is married to Schwarzenegger; Robert, a city councilman in Santa Monica; Timothy, chairman of Special Olympics; Mark, an executive at the charity Save the Children; and Anthony, founder and chairman of Best Buddies International, a volunteer organisation for the mentally disabled.

She died in Hyannis, near the Kennedy family compound, where her sole surviving brother, Senator Edward Kennedy, has been battling a brain tumour. By MARK PRATT