The Role of the court of the local sultans of the eastern territory of the Abbasid Caliphate in the development of Tanjim (Astrology)

The formation of independent and semi-independent governments, simultaneously with the weakness of the political structure of the caliphate and the decline of central supervision, caused extensive social and political changes, in addition to cultural changes Between the 3th and 8th centuries in areas of the Islamic world. At this time, the sultans' court became the center of migration of scholars and scientists. Astrologers, as predictors, found a strong and effective position in the court of sultans. "Astronomical tables" or "zijs" are some of the tools of astronomers that predict future events in the Medieval era. the main question of this article is_Considering the position of astrology in the political functions of the local sultans_what are the effects of their (local sultans) functions on the geographical distribution of astronomical tables between the 4th and 8th centuries, and how it has happened in that time period? historical method is used to describe and analysis data in this article.The findings of this article shows that between the 4th and 8th centuries, there was a change in the location of compilation of astronomical tables from Baghdad to other areas of Islamic territory, especially Iran and beyond the river. Also the construction of observatories in these areas, the writing of exacted zijs in the name of local rulers, and the writing of zijs in Persian language are some examples of the influences of the sultans.