Nearly two centuries after the slave trade ended in much of Europe, a group of campaigners and historians is lobbying European and African governments to recognize the practice as a crime against humanity.
In 2001, France became the first and only European country to pass a law recognizing slavery as a crime against humanity.
But a group based in the southern French city of Bordeaux has begun writing to leaders of other former European slave states to formally recognize slavery and the slave trade as criminal acts.
The group is called the European Memorial Foundation for the Slave Trade. Its head is 39-year-old Karfa Diallo, a native of Senegal who migrated to France 30 years ago.
Diallo says his group aims to make people aware of the consequences of African slavery. He says the scars are still evident today in the form of racism and discrimination. The foundation is lobbying not only European, but also African governments to give slavery a more prominent role in history - notably by recognizing it as a crime against humanity. Diallo's work is supported by prominent French and American historians.
Diallo also believes countries that participated in the slave trade should make reparations. He offers no specifics as to how or who would benefit from such acts. But he believes it is possible to calculate the numbers of hours slaves toiled for their masters without pay.
Besides France, Portugal, Britain, the Netherlands and Spain participated actively in the slave trade. In 1552, for example, black African slaves made up about 10 percent of the population of Lisbon, the Portuguese capital.
Diallo's group is also active in its home base of Bordeaux, which was once a prominent slave port. The Foundation wants the city to rename some two dozen streets that still carry monikers honoring families of prominent slave traffickers.
Diallo says Bordeaux officials have rebuffed his efforts. But other former slave hubs, including Nantes and Le Havre in France and Bristol in England, appear more open to the initiative.
In Africa, where many countries are marking their 50th anniversary of independence from colonial rule, Senegalese lawmakers voted in March to recognize slavery as a crime against humanity.