South African Nobel Peace Prize laureate Desmond Tutu, who used his church pulpit as a platform to help bring down apartheid, officially retired from public duties on Thursday.
Tutu, whose last major appearances came this summer when South Africa hosted the soccer World Cup, said shortly after he would step out of the spotlight to spend more time at home with his family.
U.S. President Barack Obama said in a statement: "For decades he has been a moral titan, a voice of principle, an unrelenting champion of justice, and a dedicated peacemaker.
"We will miss his insight and his activism, but will continue to learn from his example. We wish the archbishop and his family happiness in the years ahead," Obama said.
Tutu was out of the country on a cruise.
The congenial Tutu said in July in a televised news conference he would step away from public life when he turned 79 on Oct 7.
"The time has now come to slow down, to sip Rooibos tea with my beloved wife in the afternoons, to watch cricket, to travel to visit my children and grandchildren, rather than to conferences and conventions and university campuses," Tutu said.
Tutu, who retired more than a decade ago from his post as the Anglican archbishop of Cape Town, has established a peace foundation and advised political leaders.
Known at home as "The Arch", he has said he will continue his work with his foundation and a council of global statesman known as The Elders.
He said he would step down from a university post in South Africa and his work with a U.N. commission on preventing genocide and would no longer give media interviews.
Tutu's position in the church gave him a prominent national platform from which to criticise the apartheid system and call for equal rights and education.
His outspokenness incurred the wrath of the white minority-ruled South African government, which tried to prevent him travelling by revoking his passport. This move was reversed after intense international criticism.
In 1984 he was awarded the Nobel Peace Prize. Two years later, he became the first black Archbishop of Cape Town.
Pressure on the government was mounting and talks with the African National Congress led to the release from prison in 1990 of Nelson Mandela and the dismantling of apartheid laws.
Following national elections in 1994, the new President Mandela appointed Tutu as chairman of the Truth and Reconciliation Commission, the body charged with examining the human rights abuses of the apartheid years.