Black teas's production started in the Wu Yi area of the Fu Jian Province, south-east China during the Ming dynasty (1368-1644). The first product is believed to be the Lapsang Souchong.
Black tea is the second largest tea family of all teas (after green tea) and are fully oxidised (mediated by enzymes) at production. Different from the other less oxidised teas such as green teas, white teas or Oolong teas, black teas have gone thorough the most bio-chemical changes during the production. The result is the significant increase in their aroma, deeper brew colour and smooth texture.
They are some features that are unique to black teas. Valley offers some information here.