Three paintings by artist Francis Bacon are expected to reach up to �2m when they go under the hammer.

The works, including Man in Blue VII, form part of a post-war sale at Christie's in London on 6 February.

The earliest Bacon work featuring in the auction is Man in Blue VII, painted in 1954 and valued at between �500,000 and �700,000.

It was the final work of a series of pictures of the same title that he painted while staying in the Imperial Hotel in Henley-on-Thames, near where his lover Peter Lacy lived.

The second Bacon piece is Head, painted in 1962, depicting the abstract head of a surgeon with a lamp strapped to his forehead.

The auction also features the bright canvas entitled No 15 painted by Russian-born artist Mark Rothko, which has a high estimate of �1.2m.

Bacon was one of the last century's most successful artists, earning more about �14m before his death in 1992.

Violence was prevalent in much of his work, reflecting the turbulence of his own life.

His relationship with Mr Lacy was punctuated by fights that often resulted in Bacon's canvases being vandalised.

Experts believe the head of the surgeon is reminiscent of Mr Lacey, who died in the same year the painting was completed, 1962.

Violence is also a theme in Portrait of Man with Glasses IV, which shows an distorted face that looks to have been in a heavy fight.

The 1963 painting is estimated to fetch up to �400,000 at Christie's.

A series of three paintings by Bacon of his long-time partner John Edwards sold for �3m in 2001.