Paralympic champion Jon-Allan Butterworth has announced his retirement from professional cycling.
During an 11-year career with the Great Britain cycling team, the former Royal Air Force weapons technician won four Paralympic medals.
In his debut event at the 2012 London Games, he won three silver medals.
Four years later, he went one better with a gold medal in the team sprint during the 2016 Rio Games.
Butterworth's military career came to an end in August 2007 when he was injured in a rocket explosion at Basra Air Station, which resulted in the amputation of his arm.
Just 10 weeks later he took part in a Paralympic Talent ID day in Loughborough and his cycling career began.
The Birmingham-born athlete was selected for the Para-cycling Talent Programme in 2009.
That programme was created thanks to Help For Heroes' partnership with British Cycling, and in 2011 Butterworth debuted at the World Championships in Italy.
That appearance saw him set the world record for the C5 Kilo but it was at the Paralympic Games where he created history.
The kilo, individual pursuit and team sprint events were the three silver medals that he claimed in 2012.
However, four years later, he became the first ex-British serviceman to win a Paralympic gold medal in Brazil.
He also won four world titles during his cycling career.
Speaking to British Cycling about his retirement, Butterworth said: "I have enjoyed a long and successful career on the Great Britain Cycling Team.
"My proudest achievement is becoming the first British ex-serviceman to win a gold in Paralympic history.
"On reflection at the end of this strange year, the time feels right to retire from professional cycling so that I can focus my energy on the next step of my career."
Cover image: PA.