*NELSON MANDELA* - HUMAN GREAT

SOUTH AFRICA on Wednesday marked  100 years since Mandela's birth, with Barrack Obama hosting a  youth leadership  project  as Archbishop Desmond Tutu led emotional tributes to the late and anti-apartheid Icon.

Mandela's birthday on July 18 is celebrated annually around the world with  charitable works  and  the Nelson Mandela Foundation called for people to "take action and inspire change" in his name on the centenary year.

In Johannesburg, Obama told 200 young people/students attending a Leadership course he has set up that Mandela had been a key inspiration in his life.

"Most people around the world think of  Mandela as an older man, with hair like mine," he joked. "What people don't recall is that is  that he started  as a very young man -your age- trying to liberate his country. He then inspired me."

Obama on Tuesday delivered  the centrepiece address of the celebrations  to a crowd of 15,000 at a cricket stadium.

Retired archbishop n Desmond Tutu , 86, recalled fond memories of his fellow campaigner against  white-minority rule and fellow Nobel Peace Prize winner.

"The most extraordinary thing about  Nelson Mandela was his ordinariness. He was just a particularly fine example of  humanity, " Tutu said in a video message.

"The principle on which he led his life are  universal principle of love, fairness and respect of others built on understanding of the  vulnerabilities that we all share."

Machel Graca, Mandela's widow, led a short walk to promote Mandela's legacy, while the centenary was marked with the release of a new book of his prison letters and a  commemorative bank note.

Among a series of  exhibitions, music festivals and sports events worldwide, a memorial stone was also unveiled at a special service in London's Westminister Abbey.

Mandela was imprisoned under apartheid rule in 1962 and only freed  in 1990, when he went on to lead the African Nation Congress party to victory in the first multi-race elections in 1994.

He served one term as president before  stepping down in 1999. He died in 2013.[AFP]