The development of the Avestan alphabet was initiated by the need to represent recited Avestan language texts correctly. The various text collections that today constitute the canon of Zoroastrian scripture are the result of a collation that occurred in the 4th century, probably during the reign of Shapur II (309–379). It is likely that the Avestan alphabet was an ad hoc[1] innovation related to this – "Sassanid archetype" – collation.