Plaques turning the spotlight on Lisbon's role in slavery and "silenced" African history have been installed in different locations across the city, a long-awaited moment for many given the country's lack of acknowledgement of its colonial past. From the 15th to the 19th century, more than six million Africans were kidnapped and forcibly transported by Portuguese ships and sold into slavery, primarily to Brazil, but little is taught in schools about it and Portugal's colonial past is often seen as a source of pride.