Michel Pessel. The book Journeys to Mustang and Bhutan.
In 1964, Michel Pessel traveled to Mustang, a little-known Nepalese principality with a Tibetan-speaking population. The book about this journey, Mustang: The Lost Kingdom of Tibet, published in 1967, became an international bestseller. After reading this book, the King of Bhutan invited Pessel to travel through his country and write the same book, making Michel one of the first Europeans to cross into the eastern part of Bhutan.