Geography as a platform for history has always played an important role in shaping historical developments. Statement of the geographical situation of a region in terms of location and climate makes it easier to understand political events and even understand many obscure historical issues. This research is a type of qualitative research that seeks to find the geographic factors affecting the formation of the boundaries of the Taherian government. The reliance of historical sources on the reporting of political events has unintention caused historians and narrators to be underestimated ally where the events took place. Accordingly, non-historiographical sources, especially geographic books, have been used to identify Taherian territory, so far, the role of the geographic factors in the formation of the frontiers of the Taherian government has not been the subject of in dependent research, and only in some books related to the history of the Taheri dynasty have been tran siently and generally referred to the limits of their political geography.
In the present paper, the borders of Taherian keeping the historical order of the rulers of Taheri. Finally, by referring to the map sin some valid domestic and foreign atlases, the degree of compliance of written sources reports and these maps has been proposed as a new map validation.

Although Taherians have ruled in Khorasan from 205 A.H. to 259 A.H. but their political activities started from the late second century and during the Amin and Manoon conflict.This article discusses their political behavior towards the Abbasid Caliphate during that period.However’ some authors believe that Taherians are the first Persian dynasty who sought independence but the paper claims that they have only been the agents of Abbasid Caliphate and have adapted political behavior against the Caliphate.

Economic Cooperation Organization (ECO) is one of the institutions that have been established to help identify and resolve the problems faced by the region. In order to celebrate the ECO day, a meeting was held at the Center for Graduate International Studies, Faculty of Law and Political Science, University of Tehran as attended by Yahya Maroufi, ECO Secretary-General, Mr. Taherian, ECO Under-Secretary-General, Elaheh Koolaee, Director of the Central Eurasia Program, Ebrahim Mottaghi and Davoud Aghaei, professors at Tehran University. In this meeting, cooperation among nations particularly among the neighboring countries with common culture and religion was underlined and reasons for success and failures in the Organization were discussed.

The Iranian influence in the administrative affairs of the Abbasid khilafah was not limited to merely such dynasties of families as the Taherian or the Al-e Sahl, Al-e Barmak, Al-e Bakhtishu' and Al-e Nowbakht. Rather, many individuals, without being related to any prominet family, reached high-level civilian and military positions in this period. The paper before you tries to introduce one such individual called Abu Hafs Amr, or Umar Ibn-i Azragh Kermani, a literary and political figure and a historian of Mamun's era.

In the second half of the 3rd century of Hijri, Khorasan was the battlefield of warring military forces for more than two decades. By overthrowing the Taherian, the Saffarian sought to consolidate their rule over Khorasan, and after the fall, the Taherian were trying to revive their government based on the acceptability and legitimacy of the Abbasi caliphate charter and using former military personnel. Due to the lack of legitimacy, the military commanders sought refuge with the Tahirian and read a sermon in the name of Muhammad bin Tahir. The conflict between these forces resulted in the political and military instability of Khorasan. The Abbasi caliphate, based on its legitimizing power, granted the charter or disapproved of the antagonists based on their interests and interests. This approach of the caliph was one of the factors affecting the lack of definite superiority of one of the parties and numerous campaigns, which caused the military instability of Khorasan in this historical period. The present article, written with a descriptive-analytical approach and based on first-hand historical sources, aims to answer the question of what role the policies of the Abbasid Caliphate played in the military conflicts of Khorasan in the second half of the third century. The findings of the research show that the necessity and expediency was the main motivation of the Abbasid caliphate in adopting a policy against the political and military events of Khorasan, and this was the approach of the influential authors along the military disturbances of Khorasan in the second half of the third century AH.

Khorasan’s's strategic position in the events of the first five centuries Islamic, researcher of the field of Khorasan’s real inference in the Middle Ages, convened them carefully. That the geographical Khorasan, what developments has seen and these developments, affected by what has been spheres, is among the issues that the state at this point of it, affected. This article, sought to prove the point of view is that about geographical Khorasan in the period, the problem the administrative and political situation has been the province and with changing the function”, about Khorasan also changes. Disregarding these developments scholar of Islamic history, he analyzes historical developments in Khorasan, a misunderstanding of the facts, will suffer. Geographical limits of the first and second centuries AD in Khorasan, a function of the administrative system of the Sassanid era and the formation and Samanid dynasties Taherian in the state, according to the political situation and new office developments that major changes in the administrative system of Khorasan and Transoxiana independence of Khorasan. This research methods of historical research has been done and sought to give insigne about geographical changes in Khorasan and the reasons for it.

The 10th century AH was very important for Muslim lands, including Yemen in the era of Taherian (858-945 AH), because during this time, Portugal as a colonist country, in order to have access to new maritime routes, to seize Muslim commercial centers, as well as monopoly of Indian medicine trade, was moving eastward, into Yemen. At the same time, the Ottoman Empire, which was one somehow the flagship of Islam in the world, entered Yemen to save the Muslim cities and islands of India, and regarding the important commercial and strategic position of this land, dominated it in 945 AH. The present study, using a descriptive-analytical method and referring to Arabic and Turkish resources and manuscripts, seeks to answer the question: "What were the reasons for the Ottomans to attack Yemen and what were the consequences and results of the attack?" The results of the study indicate that the Ottomans treacherously entered Yemen in order to destroy the Portuguese, as well as to secure the Islamic city of Mecca and Medina, with the deception and murder of the Muslim Sultan of Yemen, which resulted in consequences such as creating many problems for the Ottomans and also lack of public trust in them.

Dir al Ugloo war was one of the major battles in the 3rd AH century in which the expansionist power of Safarian opposed the Abbasi caliphates who recently had released themselves from Torkan's predominance. The grounds for confrontation with Abbasi caliphate had been provided for Yacoub Leis Safari by occupying kerman and Fars ,but terminating Taherian dynasty by Yacoub was an end point to the negligence in Safarian's not very good relations with caliphates. The research hypothesis is that Safari army which caused Yacoub succeeded in previous battles led to his failure in Dir al Ughol war. The heterogeneous structure of Yacoub's army some of whom tended the Abbasi caliphate,inhibited the caliphate suppression. The present research has been written in a analytical _ descriptive method relying upon the first hand historical resources. The research 's main question is that how the structure of Safarian army affected the Dir al Ughol war? The present research concluded that the heterogeneous structure of Safarian army was the most important element of Yacoub failure in Dir al Ughol war which affected the military function of Safarian army significantly and Yacoub failed to recover his army 's defects  induced by Dir al Ughol war.

The Kamkars were an Iranian family in the first centuries AH and one of the renowned peasants in the Khorasan region (c. 309-31 AH). The appellation of this family comes from and is attributed to Kamkar, the Marvi peasant and one of the sons of Yazdgerd III, the last Sassanid king (632-651 AD). Some members of this family held positions in the administration system of Taherians (255-259 AH), Saffarians (247-339 AH) and Samanids (261-395 AH). The present study investigates their national and military positions by adopting a descriptive-analytical approach. This family, ruling over parts of Khorasan, was the commander in chief of the Khorasan Army. A prominent figure of this family was Ahmad ibn Sahl ibn Hashim (d. 307 AH). His father and brothers were also secretaries and astronomers. Aside from their political-military role, this family played a crucial role in the preservation of Iranian science and culture by patronizing authors and scientists.

“The Effect of COVID-19 Vaccination on Reducing the Risk of Infection, Hospitalization, and Death in Isfahan Province, Iran.” by Ziba Taherian, Mostafa Rezaei, Asefeh Haddadpour, Zahra Amini, Iran J Public Health, 51(1), Jan 2022, 188-195. The above article, published online at https://ijph.tums.ac.ir/index.php/ijph/article/view/26539 has been retracted by agreement between the authors & the journal's Editor-in-Chief. After post-publication peer review, some concerns were raised on the terminology used in the results, discussion & related analysis. Some dates were reported incorrectly & there were some inconsistencies in reporting vaccine brand names. In addition, some unintentional errors have been found in the paper typesetting. The retraction has been agreed by all panel of authors mentioned in the paper, so that the necessary corrections and completing the analysis are being made properly.