Some of the ground covered by the book may be familiar to history buffs: from the high-stakes conquest of England to the fighting qualities that Normans brought to the near-miraculous triumph of the First Crusade.
Coming suddenly round a corner into a glade of silver birch trees Edmund saw the ground covered in all directions with little yellow flowers - celandines.
There, all buildings were demolished and the ground covered with sand to provide a clear line of sight for the hundreds of guards ordered to shoot anyone attempting to cross.
But what with zigzags, devious ways, offsets to country seats, curves to farms, looped courses, and triangles to outlying hamlets, the ground actually covered by him was nearer one-and-twenty miles.