As elsewhere, roads in England have developed over many years. Perhaps some of the A151 lies on lines which are pre-Roman. In other words, parts are two thousand or more years old. However, change is constant and little of the road is that old. In the nature of things, these changes are poorly or not at all documented, so will be treated generally, in that light, in an overview below. The historical part of the story begins with the turnpike roads.