British Olympic gold medallist Jessica Ennis-Hill has announced her retirement from athletics with immediate effect.
The 30-year-old won Olympic gold in the heptathlon at London 2012, silver at Rio 2016 and is a two-time world champion.
Ennis-Hill released a statement on her Instagram account saying it was "one of the toughest decisions" she has faced but "retiring now is right".
Ennis-Hill won heptathlon gold in 2012 after she claimed victory on Super Saturday, which also saw Mo Farah win the 10,000 metres and Greg Rutherford take the long jump crown inside the Olympic Stadium.
She won by 306 points ahead of Germany's Lilli Schwarzkopf with a total of 6,955 but was unable to defend her title this summer when she finished runner-up to Belgium's Nafissatou Thiam by just 35 points.
Sheffield-born Ennis-Hill had taken time out between the Games to have son Reggie, missing the 2014 Commonwealth Games, and did hint about retirement immediately after winning silver in Brazil.
"It's going to be a tough decision, I'm going to go away and think about it," she told the BBC at time time. "At this moment, I'm tired and emotional, it's a big decision."
She returned after the birth of her son in July 2014 to win the World Athletics Championships in Beijing last year having already achieved the qualifying standard for Rio.
It was her second world heptathlon title after winning in Berlin in 2009 while she also claimed silver two years later.
Ennis-Hill's senior breakthrough came in 2006 when she won bronze at her only Commonwealth Games - finishing behind winner and team-mate Kelly Sotherton - while she also won gold at the 2010 European Championships and the World Indoor Pentathlon title the same year.
Ennis-Hill's heptathlon record:
Four major outdoor gold medals
The victories were part of her dominance of the sport between 2009 and 2012 ahead of glory at London 2012.
She won the 100 metres hurdles before coming sixth in high jump and 10th in shot put. A personal best of 22.83 seconds saw her second in the 200 metres and Ennis-Hill was also second in the long jump before throwing 47.49 metres, a personal best, in the javelin to finish 10th and put her on the brink of the title.
She completed victory with a season's best of two minutes and eight seconds in the 800metres to win the race and the Olympic crown.
Team GB Chef de Mission for the Rio 2016 Games, Mark England, praised Ennis-Hill's "glittering career", saying that he did not see her announcement coming, but added: "What a wonderful way to end a glittering career, to bow out at the top."
"She's probably the finest all-round female athlete that this country has ever produced," Mr England added, recounting her "infectious smile" and the calmness with which she approached her sport, something he said which was very beneficial to younger athletes.
Mr England added that the Olympian was a "great role model" and that Team GB "would bite her hand off" if Ennis-Hill wanted to get involved with Tokyo 2020 in roles such as offering her experiences to athletes.
"I know it will have been incredibly difficult for Jess, but I am pleased for her that she has been able to make the decision and can now look forward to a much deserved retirement," said British Athletics performance director Neil Black.
"The entire performance team of coaches, athletes and support staff will miss her at events. Not only has she competed at the highest level, but she has been a warm and positive presence within the GB team and a great example to the younger team members.
"Her record as an athlete is phenomenal and that's without considering the challenges of returning from pregnancy to win world gold and Olympic silver.
"I'd like to thank her not only for her contribution to the GB team over the years, but additionally for being a great person to work with, know and support."