Olaudah Equiano (1745-1797) was a writer born in Nigeria, and he spent his lifetime in England and in its American colonies. He wrote about his personal experience of being traded as a slave when he was 11 years old.
He was properly educated by one of his masters, Robert King, and he was able to buy his freedom after participating in some his next master's merchant activities. Once he was a free man, he became a sailor and started travelling all over the world.
In England in the 1780s, he joined the abolitionist movement. He became the first African slave to write his memoirs, explicitly describing the hardships and the humilliations suffered.