From the 1570s, African people were forcibly brought to London from the African continent. The London newspapers of the 17th and 18th centuries carried advertisements offering slaves for sale, whilst other newspaper advertisements attempted to find runaway slaves. There are also records of slaves being bought and sold on the London Stock Exchange. However, most British slaves were taken from Africa to the British colonies in the West Indies and at the start, slavery remained hidden from the general population. Read more about the 200th anniversary of the abolition of the Transatlantic Slave Trade and London's role now.
Source: Mayor Of London's Office