It seems not to be as well known as its companion and is less available. I found it in a library and it looked as if it hadn’t been borrowed for decades.
The Princes of the title are tribesmen living on the borders of Tibet and China, known to the Chinese as Lolos but calling themselves Yi.
Goullart lived and worked in the area for a couple of years and got to know the people well. He travelled extensively, often in dangerous situations, and met local people at all levels of society. When he finally had to leave, he had to do so in a hurry, having stepped, unwittingly, on a few toes.
The book gives a vivid description of the area, its wildlife, scenery and inhabitants. He was there just as the modernisation of China was starting and the world he describes is now gone. We are lucky to have such a good writer to record it.