Here's another website that I found which provides "A capsule history of Black Settlement in Britain's Capital"

http://www.chronicleworld.org/

The Shaping of Black London

AD 50 Roman London
Earliest Londoners come from all over Europe and Africa

Africans served in Roman army. "Negro head" carved wooden spoon found at Southwark bridge is earliest African connection in Southeast London.

16th century
Black trumpeter at court 1507; and "John Blanke" served Henry VII at Greenwich and later Henry VIII.

Catherine of Aragon lands at Deptford in 1501 with her African attendants.

1555 "Certain black slaves" arrive from Africa with John Lok; and marks beginning of continuous Black presence in London.

Late 16th century, opening up of West African trade. Africans became part of London's population in seafaring centres like Deptford.

1593 First record of black person, "Cornelius", in parish register 1593.

1596-1601 Fear of increased black population in London and other towns leads to Royal proclamation by Queen Elizabeth I to arrest and expel all "Negroes and blackamores" from her kingdom.

Mid-17th to late 18th century
First era of large scale settlement of blacks in Britain.

Spans period of Britain's involvement in the tri-continental slave trade.

Black slaves were in attendance as sea captains sauntered through the streets.

In Tottenham, All Hallows Church baptismal register records "John Cyras, Captain Madden's black" in March 1718, and at St Mary's Church, Hornsey "John Moore, a black from Captain Boulton's" 8th October 1725 and "Captain Lissles black from Highgate" in 1733.

etc.