The Arab conquest of Sasanian Persia in the seventh century CE, and the centuries of gradual Islamization that followed, transformed the Zoroastrian priesthood from an imperial institution with courts, secular offices and state backing into a minority clergy serving a shrinking religious community. Boyce's account traces how court priests and priests holding secular administrative roles disappeared first and fastest, since those positions depended directly on a Zoroastrian state that no longer existed, while priests serving fire temples and performing life cycle rites for ordinary believers proved more resilient, surviving where a Zoroastrian population remained to support them.
Two main Zoroastrian priestly lineages continue this office today: mobed families in Iran, concentrated particularly around Yazd and Kerman, and priests serving the Parsi community of India, descended from Zoroastrians who emigrated from Persia beginning around the tenth century to escape persecution and preserve their faith. Priesthood in both communities remains hereditary, passed through specific priestly families, a structure that has both preserved ritual continuity across many centuries and limited the number of qualified priests available as those communities have shrunk in the modern period.
Fire temple service remains the priesthood's central and most visible duty: tending the sacred fire, which in the highest grade of temple is never allowed to go out and is fed according to strict ritual protocol, alongside performing the naujote initiation that admits a child into the faith, funerary rites, and the calendar of seasonal and life cycle observances that structure Zoroastrian religious life for the laity the priesthood serves.