London has hosted the Olympic Games on two past occasions, in 1908 and 1948, with a third scheduled for 2012. The planned 2012 Summer Olympics will make London the first city to have hosted the modern Games of three Olympiads. London is the only city in the United Kingdom to have ever hosted the Olympics; the United States is the only country to have hosted Summer Olympics on more occasions than the UK.
British participation in Olympic events, both as a competitor and as a host, is the responsibility of the British Olympic Association.
2012 London Olympic Full Schedule and Results:
http://www.london2012.com/schedule-and-results/