It's pricey but, oh my God, it is worth every penny.
This is a book which has to be seen to be believed. It is amazing that 5,000 years of hairstyles can be covered so thoroughly and so interestingly.
This is not your usual glossy "one step up from a fashion mag" collection of a handful of photographs with a more-or-less vapid accompanying text. This is the business - the authoritative work. Nothing else like it before it came out in 1965, and nothing to touch the latest edition (which is updated to the year 2000).
Here's the deal. For every period, there is an essay with contemporary quotes (many of them very funny) giving the clearest insight available into the hairstyles of men and women, rich and poor, fashionable and conservative - covering, also, beards and moustaches. After the essay, there are pages of line drawings illustrating a cross section of about 20 hairstyles for the appropriate period. That is, 20 for men. Then a separate page of 20 for women. This is in itself remarkable, since men's styles generally receive much less attention than women's. Each drawing is given a date and an explanation, e.g. whether it was fashionable or conventional, or which individual wore it (if a famous person). You are talking about literally thousands of images here.
For earlier periods, the fashion might not change for 100 years. But by the time the book reaches the modern period, the book is giving you the low-down, and the plates of 20 varied examples per sex, for every ten years. It's amazing.
The book was originally designed for the theatre, so that authentic styles could be adopted. But it quickly became a cult for fashion historians and it is compelling reading for the general reader - whether as a piece of social or art history, or as a source of brilliant ideas for interesting and original styles which could look good today.