Norwegian marathon runner Grete Waitz has died at the age of 57 following a six-year battle with cancer.
A former Oslo schoolteacher, Waitz won the London Marathon twice, the New York City Marathon nine times and took the silver medal at the 1984 Olympic Games.
She won her first New York Marathon in 1978, setting a world best of two hours, 32 minutes and 30 seconds.
Waitz also won the gold medal in the marathon at the 1983 world championships in Helsinki.
Norwegian Athletics Federation president Svein Arne Hansen said: "Grete is in my eyes one of the greatest Norwegian athletes of all time, not only through her performances in the sport, but also as a role model for women in sports."
In a Twitter posting, marathon world record-holder Paula Radcliffe, who was friends with Waitz, remembered her as "an amazing champion and more amazing person".
And International Association of Athletics Federations president Lamine Diack stated: "One of the brightest flames of the modern athletics era has been extinguished but the heroic deeds of Grete Waitz will live on eternally.
"The dedication, perseverance and fortitude with which Grete carved out her athletics career on the track, across the country and on the road is an example to us all, as is the positive way she tackled the illness that beset her life in recent years.
"On behalf of the international athletics family I wish to express our heartfelt sorrow at the passing of such a great champion, and offer our sincerest sympathies and condolences to her family and friends."
During her impressive career, Waitz also competed in the 1500m at the 1972 and 1976 Olympics but missed out on the 1980 Moscow Games because of the American-led boycott.
Amazingly, her record-breaking debut in the New York Marathon in 1978 was the first time she had attempted to run the distance and only came about because her husband, Jack, talked her into trying.
In 2008, Waitz recalled the way she was feeling 18 miles into race.
"I was hurting. I was mad. I was angry. I told Jack: 'Never again,'" she said.
However, this would be the first of nine marathon victories in the city, the last coming in 1988.
Her two marathon wins in London came in 1983 and 1986.
She broke the world record three more times: in New York in 1979 and 1980 and in London in 1983.
In addition, she earned five titles at the world cross-country championships from 1978-81 and 1983.
Waitz started undergoing cancer treatment in 2005 but rarely discussed her condition in public.
Manager of the Active Against Cancer Foundation in Norway, Helle Aanesen, who got to know Waitz through her work with the foundation, commented: "She didn't wish to put too much focus on herself and her disease but hoped she could contribute in some way to help others.
"She was a fantastic and immensely successful sports practitioner and also a role model and pioneer in women's sports. She showed that women too can run longer distances than 1,000 metres."
Aanesen said a private funeral ceremony is planned for next week, according to Waitz's wishes.
Waitz is survived by her husband Jack and her two brothers, Jan and Arild.