The advent of Abbasids resulted in fundamental changes in government. The development of knowledge and thought accelerated in a new background which was formed by Abbasids, and its manifestation was "translation movement". Therefore, philosophy and theology as the important indicators of thought experienced important changes due to the new situation.In this article, the attitude of first Abbasid Caliphs to philosophy and theology; their motivations in challenging with them; their influence on the development of these knowledges; the interaction of theological sects and theologian with caliphate; and the process of these interactionsin the development of philosophy and theology, are considered.

As the most of Muslim sultans, Delhi sultans had been loyal to the Abbasid caliphate for being legitimate. Symbolic acts such as minting caliphs name on the coins and bringing caliphs name in the sermon by most Delhi sultans that their official religion was Hanafi reveals the fact that they theoretically were faithful to the caliphate system. Some of these sultans according to the political conditions in their time and to excel upon their rivals and attract support the Indian subcontinents Muslims that were mostly Hanafi or Shafei, established relation with the Abbasid caliphate of Baghdad and Cairo and received the permission of ruling from them. In this article, the relationship between the sultans and Abbasid caliphs of Bagdad and Cairo and their motivations and reasons for the establishment of these relations have been studied.

Abbasid caliphs have always used boon-companions in planning affairs, making policies and spending time. Boon-companions has been accompanied by caliphs at most of the court ceremonies especially feasts, and sometimes at consultation meetings and acted according to their skills, knowledge and abilities depending on the circumstances and the caliph’ s desire. The main question of the study is that how was boon-companions position and function in Abbasid court? This study by analyzing data and reports of the first-hand references has indicated that boon-companions sometimes had dominance over caliphs, and interfered in the affairs of the country by their views and suggestions. Moreover, due to the close relationships with caliphs, they were influential in social affairs according to the personality, adequacy and court’ s conditions. Similarly, in regard to economy, boon-companions due to their relationships and companionships by caliphs gained enormous wealth by receiving various gifts and tips and even high-ranking governmental positions and were among the properties of the court.

Despite the peak of medical knowledge in the Abbasid period, the presence of famous medical families in the Abbasid court, translation and writing of medical works, attention to nutrition and health in the court of the Abbasid caliphs, the expectation of long life and quality was created for the Abbasid caliphs. However, all these possibilities were not used much by the caliphs, and if they had not been killed in the war, they would have died of disease, even at a young or middle age. This research is performed using library sources and descriptive-analytical method. According to the findings of this study, the urgent need of the Abbasid caliphs for "treatment" had caused physicians to be present in the court of the caliphs with great benefit of wealth and even power. Revelry, the unjustified lifestyle in having fun and spending a lot of time in the harem leads to the suffering from of some Abbasid caliphs in their age Young or untimely due to some incurable or incurable diseases that caused their premature death. Finally, among the 37 Abbasid caliphs, 30 of them were killed in internal or external wars and conflicts. The remaining number died of disease, despite the establishment of a coherent system of health and treatment and having all the medical facilities of their time. Therefore, despite the provision of medical facilities for the Abbasid caliphs, the wrong lifestyle and full of excesses in having fun has caused them to fall ill and eventually die.

Given the constructive role of thinkers and the diversity of their functions in societies, the study of the relationship between government institutions and the scientific class is considered as an important historical study. Of course, the confrontation of the rulers with the ups and downs of their time has a major role in the historical direction of the issue. Now, by examining some political requirements, the government reasons that determined the Abbasid caliphs to pay attention to the classes of scholars and intellectuals are pointed out. The results showed that the caliphs' need for funding for Baghdad, their quest for legitimacy, their interest in engaging with Western neighbors, turning to the Ancient East, keeping pace with the Sunni majorities, and curbing Shiite control were among the reasons for the caliphate's attention to the society’ s elites. Also, alignment with pro-government groups and the control of minorities as opposed to the government has intensified this attention.

Islamic civilization reached its golden age during the period of the Abbasid caliphate. One of the manifestations of the numerous progresses in that period is the prosperity of shipping in rivers, and particularly in Tigris and Euphrates. Under the control of Abbasid caliphs, new canals and branches of rivers were dug and waterways were dredged. With different social and political purposes, the caliphs facilitated transportation in Iraqi rivers. In the article here, it has been endeavored to describe Abbasid caliphs' efforts and purposes in supporting shipping in rivers and it has been tried to explain how they benefited from so many military and commercial advantages of this kind of shipping. The findings show that these actions of Abbasids led to more government income, agricultural development, growth of urbanization, and transmission of knowledge and culture to capital of caliphate.

The Abbasid caliphate was the beginning of a new era in scientific and cultural developments. During this period, with the support of the caliphs of the first Abbasid era (232-132 AH), many works of different nations and ethnic groups were translated and a suitable space was provided for discussion, exchange, and conflict of different opinions and ideas through debate. The caliphs sought to strengthen the legitimacy of their caliphate through debate. In this study, which is interdisciplinary in history and political science and is based on library sources and descriptive-analytical approach, it was tried to ask the question, what effect did the debate have on gaining legitimacy of the first Abbasid caliphs. The findings of the study indicate that the caliphs of the first Abbasid era, for political reasons, tended to hold discussions and debates with the Alawites, Shiite Imams (AS) and scholars of religions and sects and used it as a source of legitimacy.

The form of communication with the Abbasid caliphate (132-656 AH) is one of the important issues of Iranian governments, which were formed in the 3rd century of Hijri. Al-Buyeh (322-448 AH) established their relationship with the Abbasid caliphate in the form of the Dominion Emirate and Amir al-Umara. The distinguishing point of Al Buyeh's relationship with the Abbasid caliphate compared to other concurrent governments was their obvious Iranism tendencies. The main issue and purpose of this research is to explain and analyze the pro-Iranian tendencies of the first and second generation of Al Buyeh rulers (322-372 AH) in the political and cultural-social context of their era and its effect on their relationship with the Abbasid Caliphate. The collection of historical and archaeological data using the method of library study and their description and analysis revealed the result that Azad al-Doleh Deilami entered the genealogy of his family, attributed to the Sassanians in the text of the historical report of Kitab al-Taji, in order to counter the political and genealogical claims of other ancient Iranian dynasties, such as the Bavandi family. However, despite dominating the Abbasid caliphate system, the first and second generations of the Buyeh dynasty, especially Azad al-Dole, due to political and religious considerations, limited their Iranian tendencies to mention the title of emperor and receive this title from the caliph.

Political marriage was a prudential connection between ruling families and was regarded as an effective method to achieve important governmental goals. This type of marriage became more popular from the fourth century AH onwards, simultaneously with the formation and development of semi-independent governments in Iran. Needed to establish the peaceful relations and to take advantage of the opportunities ahead, the rulers used them to solve the complex and political equations. About the role of political marriages in regulating the relations of governments from the 4th to the 7th century AH, so far has not been conducted any coherent and thematic research, especially based on public histories. The Findings of this research show that some of the Abbasid caliphs, the semi-independent governments of Al-Buwayhids, Ghaznawids, Seljuks, Qarakhanids and some local governments have benefited the most from it. The results show that governments usually established marital ties to maintain position, confronting the enemy, deepening the friendship, the peace and security, expanding the territory, and rarely threatening and humiliating. The main function of these marriages was to facilitate, guarantee and complete the agreements and sometimes was the only solution of it. The present article will explain the evidences of political marriage in regulation of the relations of governments with a descriptive-analytical method.