The United States Anti-Doping Agency said today that Lance Armstrong's US Postal Service Pro Cycling Team "ran the most sophisticated, professionalised and successful doping programme that sport has ever seen".
In light of the revelations, we take a closer look at the seven-time Tour de France winner.
1971: Born September 18, in Dallas.
1991: Signs with Subaru-Montgomery and becomes US national amateur champion.
1993: Crowned US national champion. Wins first stage in Tour de France but fails to finish. Beats Miguel Indurain to win world championship.
1994: Wins Liege-Bastogne-Liege spring classic.
1996: October 2 - Diagnosed with testicular cancer. The disease later spreads through his whole body. Founds Lance Armstrong Foundation for Cancer.
1997: Declared cancer-free after brain surgery and chemotherapy. Signs with US Postal Service team after being dropped by Cofidis.
1998: Wins Tours of Holland and Luxembourg.
1999: Claims first Tour de France title, winning four stages.
2000: Wins second Tour. Secures time-trial bronze in Sydney Olympics.
2001: Victorious in Tour of Switzerland.
July 29: Becomes only the fifth rider to win three Tour de France titles in a row.
2002: Wins Dauphine Libere and Midi Libre.
July 28: Becomes only the fourth person to win four successive Tour de France titles.
2003: Equals the record of five victories in the Tour de France, but is pushed to his limit by German Jan Ullrich, who finishes just 61 seconds off the pace.
2004: July 25 - Clinches record sixth Tour de France victory.
2005: July 24 - Wins his seventh Tour de France, two more than anyone else, before retiring.
September 6 - Claims he is considering coming out of retirement after being angered by drug allegations against him.
2008: September 9 - Announces he will return to professional cycling and will attempt to win his eighth Tour de France in 2009.
2009: March 23 - Suffers a broken right collarbone when he crashes out on stage one of the Vuelta a Castilla y Leon in Spain.
May - Appears in first Giro d'Italia, finishing 12th. Tour is somewhat marred by financial cloud over Armstrong's Astana team and the American is linked to a takeover.
June - Astana's financial issues are resolved and Armstrong is named in the Tour de France team, but with 2007 champion Alberto Contador of Spain as leader.
July - Contador and Armstrong endure a fractious relationship. Contador claims a second Tour title, while Armstrong finishes third. Armstrong announces he will launch his own squad in 2010, Team Radio Shack.
2010: January - Team Radio Shack make their debut at the Tour Down Under in Australia. Armstrong finishes 25th overall.
May - Armstrong's former US Postal team-mate Floyd Landis, who was stripped of the 2006 Tour de France title for doping, launches allegations at the Texan.
June 28 - Announces that the 2010 Tour de France will be his last.
July - Finishes final Tour in 23rd place, 39 minutes and 20 seconds behind winner Contador.
2011: February 16 - Announces retirement for second time.
May - Forced to deny claims made by former team-mate Tyler Hamilton that they took performance-enhancing drugs together.
2012: February 4 - An investigation into alleged doping by Armstrong is dropped by federal prosecutors in California.
June 13 - The United States Anti-Doping Agency (USADA) confirm they have initiated legal proceedings over allegations of doping against Armstrong.
June 30 - The USADA confirm they will file formal doping charges against Armstrong.
July 9 - Armstrong files a lawsuit in a US federal court asking for a temporary restraining order against the agency. Armstrong also claims the USADA offered "corrupt inducements" to other cyclists to testify against him.
July 11 - Armstrong refiles lawsuit against the USADA after initial lawsuit was dismissed by a judge as being a "lengthy and bitter polemic", designed to attract media attention and public sympathy.
August 20 - Armstrong's legal action against the USADA dismissed in court.
August 24 - Armstrong announces he will not fight the doping charges filed against him by the USADA, saying in a statement he is "finished with this nonsense" and insisting he is innocent. He is stripped of all his titles banned for life from cycling by USADA.
October 10 - USADA claim 11 of Armstrong's former team-mates have testified against him. The organisation say the US Postal Service team "ran the most sophisticated, professionalised and successful doping programme that sport has ever seen", with "conclusive and undeniable proof" of a team-run doping conspiracy.