The Zend Avesta is the sacred book of the Parsis, that is to say, of the few remaining followers of that religion which reigned over Persia at the time when the second successor of Mohammed overthrew the Sassanian dynasty and which has been called Dualism, or Mazdeism, or Magism, or Zoroastrianism, or Fire-worship, according as its main tenet, or its supreme God, or its priests, or its supposed founder, or its apparent object of worship has been most kept in view. In less than a century after their defeat, nearly all the conquered people were brought over to the faith of their new rulers, either by force, or policy, or the attractive power of a simpler form of creed. But many of those who clung to the faith of their fathers, went and sought abroad for a new home, where they might freely worship their old gods, say their old prayers, and perform their old rites. That home they found at last among the tolerant Hindus, on the western coast of India and in the peninsula of Guzerat. There they throve and there they live still, while the ranks of their co-religionists in Persia are daily thinning and dwindling away.

As the Parsis are the ruins of a people, so are their sacred books the ruins of a religion. There has been no other great belief in the world that ever left such poor and meagre monuments of its past splendour. Yet great is the value which that small book, the Avesta, and the belief of that scanty people, the Parsis, have in the eyes of the historian and theologian, as they present to us the last reflex of the ideas which prevailed in Iran during the five centuries which preceded and the seven which followed the birth of Christ, a period which gave to the world the Gospels, the Talmud, and the Qur'an. Persia, it is known, had much influence on each of the movements which produced, or proceeded from, those three books ; she lent much to the first heresiarchs, much to the Rabbis, much to Mohammed. By help of the Parsi religion and the Avesta, we are enabled to go back to the very heart of that most momentous period in the history of religious thought, which saw the blending of the Aryan mind with the Semitic, and thus opened the second stage of Aryan thought.

Part 1
Contains the Vendidad, one of the oldest ecclesiastical codes. Originally composed in Avesta, an early Iranian language, the text focuses on the foundation of Zoroastrianism.

Part 2
Contains the mythical lore of Yast, Sirozah, and Nyasis. A more poetic text, readers will broaden their knowledge of Zoroastrianism with this book.

Part 3
Contains Yasna, the main liturgical text of Zoroastrianism, dating back to the religion's earliest period and is still used today.

These three volumes which make up the Zend-Avesta are a subset of the Sacred Books of the East series which were first published sequentially between 1879-1910. The Zenda Avesta was published as volumes 4, 23, 31 in this series respectively. The complete 50 volume set is composed of translations of all the most important works of the seven non-Christian religions which have exercised a profound influence on the civilizations of the continent of Asia.

Friedrich Max Müller (1823-1900), was a German author and orientalist who lived in England most of his life. As a professor at Oxford, he combined the studies of language, culture, and religion to create the discipline of comparative mythology. His body of work included The Sacred Books of the East, which he had edited.

James Darmesteter (1849-1894), was born in France to Jewish parents and devoted his studies to the Persian religion of Zoroastrianism, asserting it was influenced by Judaism, contrary to most scholars. He was a noted translator and teacher with a passion for Orientalism.

L. H. Mills (1837-1918), was born in New York City and attended NYU before becoming Professor of Zend Philology at Oxford University. An authority on the Avestan language, Mills translated The Zend-Avesta, Part 3.