This is part I of the Sacred Books of the East Pahlavi Texts translation. It includes a number of crucial medieval Zoroastrian texts: the Bundahis, Selections of Zad-sparam, the Bahman Yast, and the Shayast la-Shayast, as put into writing about the sixth century [AD]. The Bundahis is of note because it is a collection of Zoroastrian traditions about the creation of the world. The Shayast la-Shayast deals with matters of ritual impurity, sin, and rituals related to purification, including many cases related to dead bodies. The Bahman Yast is a prophetic text, which details thousands of years of history, including the downfall and rebirth of the Zoroastrian faith. West compares these texts respectively to the Biblical books of Genesis, Leviticus and Revelation. (Quote from sacred-texts.com) About the Author Thomas Firminger Thiselton-Dyer (1843 - 1928) Sir William Turner Thiselton-Dyer FLS FRS KCMG (July 28, 1843-December 23, 1928) was a British botanist. Thiselton-Dyer was born in Westminster, London. Initially studying mathematics at Oxford University, he graduated in natural science in 1867. He became Professor of Natural History at the Royal Agricultural College in Cirencester and then Professor of Botany at the Royal College of Science in Dublin. In 1872, he became professor at the Royal Horticultural Society in London, being recommended by Joseph Hooker. Then in 1875, Thiselton-Dyer was offered the Assistant Directorship at Royal Botanic Gardens, Kew, under Hooker, where he was to stay for thirty years. Thiselton-Dyer spent considerable time on the Colonies, e.g. introducing rubber to plantations of Sri Lanka and Malaya, and the introduction of cacao from Trinidad to plantations in Sri Lanka. In 1877, he was given charge of an international re