According to Dead Sea Scrolls archaeologist Yigael Yadin, Aramaic was the language of Hebrews until Simon Bar Kokhba's revolt (132 AD to 135 AD). Yadin noticed the shift from Aramaic to Hebrew in the documents he studied, which had been written during the time of the Bar Kokhba revolt. In his book, Bar Kokhba: The rediscovery of the legendary hero of the last Jewish Revolt Against Imperial Rome, Yigael Yadin notes, "It is interesting that the earlier documents are written in Aramaic while the later ones are in Hebrew.