as alterations of the Greek name Χρυσης, Khrisis, or Χρυσος, Khrisos, but according to Aleksander Brückner this is unwarranted: these names are not Christian names, so there was no reason for the Serbs to adopt them, and Χρυσ- is spelled simply as khris-. Etymology In Old Russian sources, this theonym is noted as Xърсъ, Xŭrsŭ, Хорсъ, Xorsŭ, Хъросъ, Xŭrosŭ, and in modern Russian literature it is written as Khors (), similarly spelled by Maciej Stryjkowski - Khorsum (, modern ). In English, depending on the transliteration system, the name is written as Khors, Hors, or Xors. Iranian etymology Currently, the most popular view regarding the etymology of the theonym Khors is Iranian, and this etymology has been proposed since the 19th century. The Russian historian Pёtr Butkov, who called Khors "the Slavic Apollo", was one of the first to connect his name with the Persian خورشید, xuršit and the Ossetian xur, xor "sun," and with the Ossetian xorošŭ, хоrsŭ, xorsu meaning "good". Iranian xvar "halo", Indian hāra, hāras "fire" or Persian xoršid "sun", Xuršid "sun-god" are also proposed. The Iranian word was also supposed to be the root word for Krones, the sky god in the Voguls and Ostyaks, and for the word kvar "sky", "air" in the Votyak language. Vladimir Toporov believed that the name Khors was brought to Kyiv, along with the solar cult, by soldiers from Khwarazm, who were supposedly stationed there during the reign of Vladimir the Great, but this theory has been heavily criticized. Mikhail Vasil'yev stated that the name could not have been borrowed from Middle Persian, but from Sarmatian-Alan peoples in the first millennium BC (so-called Iranian inversion). Besides the Iranian etymology, there were other theories. For example, an early loan from Ossetian xorz "good" was proposed, which would also explain the Russian word хороший, khoroshiy "good," which was originally supposed to mean "of Khors, belonging to Khors", but this possibility was rejected by Vasmer. Toporov, who also rejected borrowing from Ossetian, wrote: Criticism Borrowing from Iranian languages has been accepted by religious scholars without much complaint, but linguists, such as Max Vasmer, point out phonetic problems. Iranian hva- does not explain the Slavic short vowel ъ (ŭ), and š could not in Slavic languages remain as s, but according to the ruki rule should remain either as х (h) or as š (sh) in case the word was borrowed after the rule