To the reviewer who complains that the description is misleading, that is hardly a fault of the author. The product is what it says it is, a diagrammatic history.
With respect, the criticism misses the point.
You are not paying for a book, you are paying for the work and research that has gone into the history and its presentation. You should judge the history by the quality of its information and how interesting and informative it is, and to some extent the quantity of information. Speaking personally, it's fortunate that the research has been reduced to a manageable and easily assimilable form.
It's easier to write at length than to produce a work that is lean, tight and yet full of information.
One small carp-ette. The Amazon description of the work has "diagramatic". Shouldn't it have two m's, not one?