Tributes for Eunice, the quiet heroine of the Kennedy family

Mrs Shriver died at a hospital in Massachusetts at 2am yesterday morning. She was the co-founder of the Special Olympics, set up in honour of her sister Rosemary who was born with a mental disability and who later, at the request of her father, underwent a failed lobotomy that left her unable to care for herself.

It was Mrs Shriver who revealed the very much private condition of her sister to the nation during her brother's presidency - described as the American Camelot period to reflect its hope and optimism - and later ran a summer camp for children with disabilities.

Mrs Shriver realised that the children were far more capable of sports than experts said and she pressed her parents to support duplication of the camp across the US.

She co-founded the first Special Olympics in 1968 in Chicago and visited Glasgow in 1990 when the city hosted the European event.

Now more than one million athletes in more than 160 countries participate in the Special Olympics, with Mrs Shriver having remained a presence at the organisation's headquarters in Washington well into her 70s.

US President Barack Obama last night paid tribute to Mrs Shriver. He said: "Above all, she will be remembered as the founder of the Special Olympics, as a champion for people with intellectual disabilities, and as an extraordinary woman who, as much as anyone, taught our nation - and our world - that no physical or mental barrier can restrain the power of the human spirit.

"Her leadership greatly enriched the lives of Special Olympians throughout the world, who have experienced the pride and joy of competition and achievement thanks to her vision."

Her efforts, in many ways, set her apart from her power-seeking brothers, according to some commentators.

"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," author Harrison Rainie, a Kennedy biographer, wrote in 1993.

While two of her brothers were assassinated and a further two killed in plane crashes, Mrs Shriver passed away quietly with her husband, her five children and all 19 of her grandchildren by her side. She had suffered a series of strokes in recent years.

Her only surviving brother Teddy, who himself is ill with a brain tumour, led the mourning from the Kennedy family compound close to the hospital where his sister passed away. Senator Kennedy said his earliest memory of his sister was as a young girl "with great humour, sharp wit and a boundless passion to make a difference.

"She understood deeply the lesson our mother and father taught us - much is expected of those to whom much has been given," he said.

"Throughout her extraordinary life, she touched the lives of millions, and for Eunice that was never enough."

Senator Kennedy has one remaining sibling, Jean Kennedy Smith.

Alongside warm words from Mr Obama, praise for Mrs Shriver also flowed from former first lady Nancy Reagan and Arnold Schwarzenegger, the former actor turned Governor of California who had Mrs Shriver as a mother-in-law following his marriage to her daughter Maria Shriver, a former TV anchorwoman.

Governor Schwarzenegger said that Mrs Shriver "changed my life by raising such a fantastic daughter, and by putting me on the path to service, starting with drafting me as a coach for the Special Olympics".

And Nancy Reagan, whose husband Ronald presented Mrs Shriver with the Presidential Medal of Freedom, the highest civilian honour in the US, said: "Eunice Shriver's death is a huge loss for all of us. I remember vividly when Ronnie presented her with the Presidential Medal of Freedom at the White House in 1984.

"He said then that, her decency and goodness have touched the lives of many, and Eunice Kennedy Shriver deserves America's praise, gratitude, and love'."