Ancient Iranian religion was strongly connected. Beginning in the early 10th-century BC, the ancient Iranian religion was gradually displaced by Zoroastrianism, which contains many essential aspects of its predecessor. The sources on ancient Iranian religion, though limited, consist of textual and material sources. The textual sources are both Iranian and non-Iranian. An important Iranian source is the Avesta, which are Zoroastrian sacred scriptures made in the Avestan. This is considered the principal source of knowledge on ancient Iranian religions. It is a collection of several texts that seems to have been over a large span of time by a variety of authors. These
Avesta (locality) Avesta (locality) Avesta is a locality and the seat of Avesta Municipality in Dalarna County, Sweden, with 11,949 inhabitants in 2015. The name is first found in 1303 as "Aghastadhum". "Aghe" is of similar origin as the word å, meaning stream, in this case the Avestafors, a tributary of the river Dalälven. "Stadhum" was dative plural of a word of similar origin as stead, or farm. In the Scandinavian Middle Ages there was a blast furnace at the location. In 1636 the construction of a giant copper mine was initiated near the Avesta fors. The town Avesta received partial privileges