How, why, and when the notion of happiness or joy arose, spread, changed, and became fundamental to the worldview, writings, arts, and religious and social practices of Mazda-worshipers or Zoroastrians are elucidated and analyzed. Influences into this concept from the classical world and impacts of this concept on neighboring societies are discussed in ancient and medieval contexts. Continuations and changes of this ethos from antiquity into modern times are documented and understood within the dualistic cosmology of Zoroastrian beliefs and the lives and aspirations of elites, clerics, and commoners, from the Iranian plateau eastward across Central Asia into China and southeastward to India.

Received 19 February 2026. Revised 19 May 2026. Accepted 22 May 2026. Published online 06 July 2026

Avesta, Bactrians, Central Asia, China, Cosmology, Dualism, Ethos, Gujarati, Happiness, India, Iran, Iranians, Joy, Manichaeism, Pahlavi Texts, Parsis, Persian, Sakas, Sogdians, Zoroastrians, Zoroastrianism,