history of cultural developments and metamorphosis of works written in pre- islamic era

during different historic periods, land of iran has been invaded by alien tribes and iranian written works such as religious, scientific and historic books have been subjected to detruction and demolition for several times. many historical evidences have referred to background of this issue and at the same time they testified that iranian cultural written hertage has been subjected to recovery and revival by rewriting or repeated compilation and translation. and also during islamic period, many scientific, historic and cultural writings and translations were intellectual heritage of great civilizations like iran and greece where greek heritage, of course, has also included iranian teachings because of mecedonian alexander’s invasion to persia. in this paper, we intend to consider historical documentations in this regard by exploration into cultural developments in the field of written works.