Team GB scooped 19 golds, the most since London 1908, finishing fourth in the medal table, and Adlington's heroics in the first week signalled that something special was about to happen.
The 19-year-old shocked the swimming world when she overhauled six-time world champion Katie Hoff in the 400m freestyle to win by 0.07 seconds. In so doing she became the first British woman to claim swimming gold since Anita Lonsborough in 1960.
If Adlington's first gold was thrillingly close, her second was almost implausibly emphatic. Having set an Olympic record in her 800m freestyle heat, Adlington simply pulverised a high-class field in the final, winning by over six seconds and shattering Janet Evans's 19-year-old world record.
The achievement propelled the unassuming Adlington reluctantly to fame. She came third in the BBC Sports Personality award, picked up an OBE in the 2009 New Year Honours and is considered one of Britain's leading medal hopes in London.