According to a modern etymology, the term ''Azerbaijan'' derives from that of ''Atropates'', a Persian satrap under the Achaemenid Empire, who was later reinstated as the satrap of Media under Alexander the Great. The original etymology of this name is thought to have its roots in the once-dominant Zoroastrianism. In the Avesta's ''Frawardin Yasht'' ("Hymn to the Guardian Angels"), there is a mention of ''âterepâtahe ashaonô fravashîm ýazamaide'', which literally translates from Avestan as "we worship the fravashi of the holy Atropatene." The name "Atropates" itself is the Greek transliteration of an Old Iranian, probably Median, compounded name with the meaning "Protected by the (Holy) Fire" or "The Land of the (Holy) Fire". The Greek name was mentioned by Diodorus Siculus and Strabo. Over the span of millennia, the name evolved to  (Middle Persian), then to , ,  (New Persian) and present-day ''Azerbaijan''.