Jessica Ennis-Hill has announced her retirement from athletics.
The 30-year-old won Olympic gold in the heptathlon at London 2012 and 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".
She wrote on Instagram: "Amazing memories ... from my first world title in Berlin 2009 to Rio 2016 I'm so fortunate to have had such an amazing career within the sport I love and this has been one of the toughest decisions I've had to make.
"But I know that retiring now is right. I've always said I want to leave my sport on a high and have no regrets and I can truly say that.
"I want to thank my family and incredible team who have spent so much of their time supporting me and enabling me to achieve my dreams. Also a huge thank you to all those people who have supported and followed my career over the years."
Ennis-Hill won heptathlon gold in 2012, to emulate Denise Lewis' win at the Sydney Olympics, 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.
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 teammate Kelly Sotherton -- while she also won gold at the 2010 European Championships and the World Indoor Pentathlon title the same year.
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.
British Athletics performance director Neil Black heralded Ennis-Hill as a "phenomenal" talent.
Black said: "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.
"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."