The on-line extract of this book is a total fantasy of mediaeval life. There are ludicrously wild generalisations, such as the assertion that mediaeval meat, even the most prestigious kinds, was "poorly prepared and undercooked", and that "the huts of the peasants are one-room hovels constructed of rough wood or sod" (really? That's in the whole of Europe, then, from Denmark to Sicily?) and plain untruths, such as that the peasants were deformed by rickets caused by malnutrition on a diet that included "grass as a principal staple". (Not only was there no part of Europe where grass was a normal food, but rickets is actually caused by a lack of sunlight, calcium and phosphorus - so anybody who did farm work and ate greens would be very unlikely to get it! Rickets only became common in the heavily-polluted cities of the Industrial Revolution.) The author also asserts that the jus primae noctis existed in England, something that no historian has ever claimed (in fact all serious historians now agree that the jus primae noctis is a fantasy which didn't exist anywhere in Europe). He goes on to say that the peasant farming was so inefficient that they couldn't grow enough food; "without iron tools, they can't plough the land". Tripe! Archaeology has shown that the farming technology of early mediaeval Europe was perfectly capable of sustaining good levels of production.
Then there are wild bits of Grand Guignol such as the idea that when people bit into blood sausages "the blood spurts from your mouth. You can't wipe it away." Rubbish: if you cook blood in a sausage casing it rapidly becomes dense, solid, dark in colour, highly nutritious and delicious. It's called black pudding.
If this extract is typical of the rest, then this book might make a good Monty Python sketch but can't possibly call itself history.