Zoroaster (Avestan Zarathushtra; Dari Zartosht) was the prophet of ancient Iran whose hymns, the Gathas, lie at the heart of Zoroastrianism, the faith of Ahura Mazda, the “Wise Lord”. When and where he lived is uncertain. Proposed dates run from the 2nd millennium BCE to the 6th century BCE; if there is a rough consensus among scholars, it is around 1000 BCE.
The Gathas give no clear clue to his homeland, but the geography and the dialects of the Avesta point to eastern Iran, the wider Iranian world that includes today’s Afghanistan, so most scholars place him there. Bactria, the country around Balkh (ancient Bactra), appears in the Avesta’s list of lands, praised as beautiful and “with uplifted banners”.
A later tradition went further. Historians from al-Tabari onward, drawing on Sasanian royal chronicles, set his preaching at Balkh, at the court of King Goshtasp (Avestan Vishtaspa). Scholars treat this as tradition rather than proven history: it probably owes much to Balkh’s long prominence in the east, and it was later reconciled with a rival claim that Zoroaster was born in Azarbaijan.