More than 50 years ago Nelson Mandela stood in Parliament Square and joked that one day a statue of a black man might stand there.

Yesterday the words of the former South African presidents came true as he unveiled a nine-foot bronze likeness of himself.

Thousands gathered for the ceremony opposite the Houses of Parliament.

Mr Mandela, 89, told them: "It's an honour for us to be with you on the occasion of the unveiling of this statue today.

"We never dreamed we would all be here today. Though this statue is of one man, it should in actual fact symbolise all those who have resisted oppression.

"The history of the struggle in South Africa is rich with the stories of heroes and heroines," said the Nobel Peace Prize winner. "All of them deserve to be remembered."

In 1962, Mr Mandela and his fellow anti-apartheid leader Oliver Tambo visited London to raise funds for their campaign.

"When we visited Westminster Abbey and Parliament Square... we half joked that one day a statue of a black person would be erected here."

Now his statue stands alongside those of British Prime Minister Winston Churchill, US President Abraham Lincoln and the South African statesman Field Marshall Jan Smuts.

Prime Minister Gordon Brown it was fitting that Mr Mandela, whom he called "the great liberator," joined his peers.

"Nelson Mandela is one of the most courageous and best-loved men of all time," he added.

The audience also included Conservative leader David Cameron, foreign secretary David Miliband and former deputy prime minister John Prescott.

Mr Mandela appeared frail as he made his way to the platform, leaning on the arm of his wife, Graca Machel.

But he spoke clearly as he invited the crowd to celebrate his 90th birthday next year at a concert in London's Hyde Park. It will support his Aids foundation, called 46664 - the number he wore in prison.

As he toured the square amidst the symbols of British power, Mr Mandela said: "Oliver would have been proud today if he were here."