English Breakfast tea is a black tea blend usually described as full-bodied, robust, and/or rich, and blended to go well with milk and sugar, in a style traditionally associated with a hearty English breakfast.
The black teas included in the blend vary, with Assam, Ceylon and Kenyan teas, and Keemun common. Common brands of English Breakfast tea include Twinings, Tetley, Taylor's of Harrogate, PG Tips, Stash Tea Company, Lipton, Celestial Seasonings, Ringtons Tea, Teekanne, Zesta and Dilmah.
Another explanation of its origin cites a Journal of Commerce article which dates the blend to 1843 and a tea merchant named Richard Davies in New York City. Davies, an English immigrant, started with a base of Congou and added a bit of Pekoe and Pouchong. It sold for 50 cents a pound, and its success led to imitators, helping to popularize the name.