Adele's '21' has now become the longest running number one album in the last forty years.

The London singer's second album '21' has now matched the previous record held by the Bee Gees' 'Saturday Night Fever', which also spent eighteen weeks at number one back in 1977.

There are only eight other albums that have passed Adele's record; Simon & Garfunkel's 'Bridge Over Troubled Water' spent a total of  41 weeks at number on in 1971, while others include The Beatles' 1967's 'Sgt Pepper's Lonely Hearts Club Band.'

Adele's '21' has recently been nominated for this year's Mercury Prize award, along with ith Katy B, Elbow, Tinie Tempah, James Blake, PJ Harvey, Anna Calvi and Metronomy and others.

Mercury Prize Nominees 2011