The first version of this most popular of all teas was developed over a hundred years ago by the
Scottish Tea Master Drysdale in Edinburgh. It was first marketed as "Breakfast Tea". It became popular in
England due to the craze Queen Victoria created for all things Scottish. Tea shops in London, however, changed the name and marketed it as "English Breakfast Tea". The tea is a blend of fine Indian and Ceylon black teas, other teas like the Keemun are also used. Many tea authorities suggest that the Keemun tea blended with milk creates a bouquet that reminds people of "toast hot from the oven", this may be the original source for the name of the blend. It should be offered with milk or lemon. Lemon should never be served to a guest if they request milk - it would curdle the milk. It may also be used to make iced tea.
Gathered from Stash Tea's History of Tea with bits of information from Oolong.