Brazilian President Luis Inacio Lula da Silva has apologised for his country's role in African slavery while on a visit to Senegal.
Brazil's president looks through the 'door of no return' on Goree Island
He asked for "forgiveness" in a speech at Slave House on Goree Island, from where Africans were shipped between the 16th and 19th centuries.
Brazil imported the most African slaves of any country during that time and only abolished slavery in 1888.
Almost half of Brazil's 180 million population are of African descent.
"I want to tell you... that I had no responsibility for what happened in the 16th, 17th and 18th Centuries but I ask your forgiveness for what we did to black people," said the president, commonly known as Lula.
Accompanied by Senegal's President Abdoulaye Wade, he stopped to look through the "door of no return", from where chained Africans would take the dangerous journey across the ocean to the New World.
Some of his delegation shed discreet tears, Reuters news agency reported.
Senegal is the last stop on Lula's five-nation tour of Africa.
Along with a large, mostly trade-orientated delegation, he has visited Cameroon, Nigeria, Ghana and Guinea Bissau.
The trip is an indication of the importance the Brazilians are placing on expanding trade ties with other developing countries, say correspondents.
But Lula said he also wanted to build on Brazil's historic ties with Africa.
"It's not just about reaching business deals but it's the strategy of a politician who is conscious of the historical debt towards Africa," he said.