The name is recorded in 1166 as Blachehedfeld and means the "dark coloured heathland". It is formed from the Old English 'blæc' and 'hǣth' and refers to the open space that was the meeting place of the ancient hundred of Blackheath. Popular legend is that it derives it's name from being a burial ground for either the Black Death (mid-14th century) or the Plague (mid-17th century) but this is unlikely!
Lovely mood to this, I feel cold just looking at it! Blackheath is where the Cornish Rebels fought with the English back in 1497 ... I bet it was a bit warmer that day!