Olaudah Equiano was an african writer born in Nigeria by the XVIII century who lived in England and its american colonies. He claimed to have born in a lost town named Chia near the Igbo region of Nigeria, at the early age of eleven he was took as a slave and carried to North America where he was sold firstly to a captain of the royal navy who named him as Gustavus Vassa as an insult to the Swedish king of that time.
The captain´s name was Michael Pascal and at first Equiano refused to use the name because he had been already renamed twice before during his travel in the ship, he prefer to be named Jacob, the second name they have put him, but after many tortures, acordding to him he ended up submitting to the new name. After spending a long time with Pascal in which he converted to the christianism among other things he was sold to another captain who took him to the Caribbean where he was purchased by Robert King an american quaker.
Robert set Equiano to work on his shipping routes and his stores and taught him to write and read. In 1765, when he was 20 years old King promised that for 40 pounds, Equiano´s purchase price, he could buy his freedom, action that was achieved on 1766. After that King urged him to stay as his bussines partner but Olaudah found it dangerous to stay in the british colonies specially after an intempt of kidnapping on Georgia. He travelled to England where he joined the abolitionist movement that encourage him to write and publish a memoir book named "The interesting narrative of the life of Olaudah Equiano, or Gustavus Vassa, the Afircan" in 1789.
It was an important historical source because it represented one of the first writings on western narration made by an african author. It was the first time that someone wirtes about slavery from the point of view of the slave itself. He caused surprise between the readers because of its quality of imagery, description and literaly style, he made comparissons with the bible showing his knowledge on christian religion. The publication became a best seller almost inmediatly ( 3 years after it was publish) and fuelled a growing anti-slavery movement in Great Britain, Europe and North America.
I hope this answer would help you, I put a briefly biography of Olaudah to set the context
