While there are plenty of English blends - pipe tobaccos made in England - I usually reserve the term for a flake/mixture classically consisting of Virginia, Oriental, and Latakia tobaccos.
I also consider (rightly or wrongly) Balkan blends to have a stronger emphasis on the Oriental/Latakia side of the equation.
People debate this ad nauseam but there is no doubt that they are the popular definitions here in North America. A few blends add in perique or cavendish, but that does not change their latakia character enough to warrant another classification.
People in the UK will undoubtedly consider all of their brands to be English, and rightfully so. But, for most of us here who shop on this side of the pond, the term refers to a latakia blend - newcomers would do well to expect that smoky, savoury, leathery, campfire note in any "English" blend and to steer clear if that's not their thing.