The unexpected finding of the Dead Sea Scrolls between 1947-1956 shed a new light on Jewish history in antiquity. Their final authoritative bilingual editions in Hebrew and in English or in Aramaic and in French or English became available only in the last few decades. All the unknown Hebrew and Aramaic manuscripts written on parchment, are a part of a priestly sacred library of authors who describe themselves as "The priests the sons of Zadok and their allies". In this series we'll discuss the four fold nature of the unknown books, the background of their authors and their purpose, the historical background of their writing in the two last centuries BCE in relation to the bitter dispute on the priestly calendar, and the connection of the scrolls to the ongoing conflict between the Pharisees and the Sadducees.