Abstract
In the classical society of the Sassanid era, the clerical class was one of the most important pillars of the community. It had influence, credibility and popularity, and represented an important and influential institution from the lowest to the highest levels of society. This important institution is however not well-known and many uncertainties remain about it. One of these ambiguities is the inner structure of this class, which is still almost unknown. Due to the vagueness of the information coming from various sources other than a few titles, there is almost no precise data about its hierachy. Due to the great importance of this class, a proper understanding of the Sassanid era would not be possible without a proper understanding of the clergy class. This is the topic of the present paper, mainly based on literary material. It could notably be proven that the Zoroastrian clergy of the Sassanid period can be divided into two general groups in terms of the presence or absence of governmental professions and official titles. It is not possible to determine the upper ranks of this class, such as Rad, Dastour or Mowbed, while the head of the clergy class (as the Mowbedān-Mowbed) was a member of the class known as the Sassanid privileged ones (Vozorgan).
Keywords: Zoroastrian Clergy, Sassanid Era, Structure and Hierarchy of the Zoroastrian Clergy.

Introduction
It is difficult to reconstruct the internal structure of the institution of Zoroastrianism. It is due to two fundamental factors: first, the length of the Sassanid era and the dynamics of the society that inevitably led to profound changes and transformations in various institutions during these 430-year periods.  and the second the final prophecy What happened during this time was long after the collapse of this dynasty, which was modified by the same institution in accordance with the goals and purposes of this institution and in accordance with the conditions of the time.  Thus the texts further complicate matters rather than the help solving the problems. For example, in the Sad Dar Nasr is written: “In the case of sin, one should try to repent to the Hirbads and the Dasturs and the Rads.” In this phrase, three important cleric titles or positions are mentioned without any precision concerning their precise attribution (Sad Dar Nasr, Dar-e 45). It is probably explained because the main target audience of these books were familiar with these definitions and titles, and that the authors of the texts did feel consequently the need to explain them clearly. So what is the meaning of the titles used by clerics during the Sassanid period? How did this social class evolve? Almost all scholars who worked on the Sassanid period inevitably dealt with Zoroastrianism, and consequently the institution of the clergy (Christensen, 1368. Frye, 1382. Shaked, 1384. Zarinkob, 1388. De Yong, 1390. Daryaee, 1383. Shaki, 2011. Miri. 2013 &...).

Discussion
Daryaee segregated the Sassanid clergy class “in terms of their rank and duty”, including “Mowbeds, Hirbbads, Dasturs, Dadvars, and Rads”, which meant: the senior clergy, the Fire Worshiper clerics, specialist theologians or jurists, judges and scholar clerics “ (Daryaee, 1392B: 144). It is further shown in this study that it is not possible to deal with the internal division of this class clearly. For example, while Manouchehr, the author of the letters of Manouchehr, introduced himself in his letters as the Rad of Pars and Kerman, at the beginning of his third letter to all Behdinān, he called himself the Hirbad-e Khodāy. On the other hand, some of the categories are sometimes mentioned for a specific task, so it becomes very difficult to determine exactly what each of these positions was. In the Ravayat-e Azarfranbag-e Faroxzadan, in response to the question, “If all members of a family are to be Behdin except one woman, can she become the Padehah Zan?” it is said: “Rads, Mowbeds and Dasturan have to choose a guardian for her.” There are many similar cases in Sassanid texts which make it impossible to draw any definitive conclusions in this regard. Unfortunately, seals are not really helpful as Gyselen points out: “It should be noted that glyptic does not offer anything other than a very few titles or whether the lack of findings was because some authorities needed Have they not used the seal? Or the cause of something else is unclear “(Gyselen, 1995: 123). Accordingly, this paper is divided into two parts. The first deals with the official titles and ranks of the Zoroastrian clergy and the second part deals with the informal titles.

Conclusion
- Some clerical titles correspond to official titles, employed in government offices or bureaucracies, while most of clerics were not State employed and devoted themselves solely to religious activities.
- There were clerics who had no position in the clerical hierarchy and were usually referred as clergymen with specific characteristics, such as the title of Zartoshtom, which was probably something like a polar and a disciple.
- Although it is possible to imagine Rads, Dasturs and Mowbeds in the top ranks of the clergy, it is not possible to determine precisely the position of each of these titles in the hierarchy and their priority.
- The clergy class, like other classes of Sassanid society, had a leader whose title varied in different eras. The title Mowbedān-Mowbed is only attested since the middle of this period and probably did not exist in the early Sassanid era. It is still unclear what was the title or name of the head of this class at that time.
- It seems incorrect to distinguish the titles of Mowbed and Mog (Magi), and to place them in two separate degrees in the Zoroastrian hierarchy, at least until the mid-Sassanid era. They have the same linguistic meaning. Of course, in the later periods, and given the dynamics of Sassanid society, a distinction may be drawn between these titles, in which Mowbed took precedence over Magi.

Abstract
Mehr-Narseh is known as one of the most important character of the middle Sassanid era. Based on the written historical sources, the construction of some buildings has been attributed to him, among which the most outstanding ones are five fire-temple monuments built in the southwest of Fars. Although various theories have been put forward regarding the location of the structures, by far, the nature and qualitative value of them are unknown. In this study firstly, the political-religious personality of this Sassanid minister in various ways was investigated, then besides recognizing their religious nature and value via analysis of the sources related to Mehr-Narseh fire temples, the Chahar-Taqis attributed to him was also studied, according to the current theories,  so as to reveal some features of  the religious architecture of Sassanid era. This is a fundamental or basic research, and the nature and method of which is historical and descriptive-analytical. The data is also collected from library and fieldwork. Based on the results of this study, it seems that the fire temples built by Mehr-Narseh included two separate types and four fire temples attriuted to him located in Abruwān area were related to family fire meaned “Dādgāh”. According to the field studies and similarity, the previous theories can be criticized and a new group of religious temple of Sasanian period in Farashband can be introduced that contains one or several fire temples, which are attributed to Mehr-Narseh. It seems that these kinds of fire temples have a complex plan with additional architectural and probably had a number of attendants to do the work related to the fire temple. Overall, this research can provide a correct understanding of the fire temples of “Dādgāh” Fire during the Sassanid period. This also provides a new grouping manner for such these temples and can be known as a pattern for reviewing of usage and religious value of other similar Chahar-Taqis.
Keywords: Mehr-Narseh, Fire Temple, Chahar-Taqi, Sassanid Era, Dādgāh Fire, Farashband.

Introduction
One of the important points mentioned in the historical resources is the information regarding the personality of Mehr-Narseh, as one of the significant figures of the middle Sassanid period, who built several fire temples and made other services in several other fire temples, which has been attributed to him by the order of the Sassanid emperors. Discovering the fire temples constructed under the order of Mehr-Narseh has been one of the most interesting study topics related to the religious architectures of the Sassanid period during the last century. There are different theories regarding the probable location of the fire temples attributed to Mehr-Narseh, which mainly include the region between the current Kazerun, Farashband, Dehram, and Firouzabad. This article attempts to study the fire temples attributed to Mehr-Narseh from a different perspective. In the first step, we study and explore Mehr-Narseh character to determine his political position in the middle of the Sassanid period and have an idea of his religious position in the system. The second step is to survey the nature and characters of the fire temples attributed to him from in terms of the quality value and their positions, to have a final analysis of their architectural complexities. The main question of this study is the religious quality of the fire temples attributed to Mehr-Narseh and what kind of fire was kept in the fire temples attributed to him? Also, based on the fires kept in these fire temples, what is the level of architectural complexity of the mentioned structures? The proposed hypothesis for this question is that it is possible that the four fire temples of Mehr-Narseh were containing the fire of “Dādgāh” and the fire temple of Jereh contained the fire of Ādarān. It is also assumed that the Dādgāh fore temples of Mehr-Narseh had additional spaces in the form of small architectural complexes. Based on the purpose of the study, this is basic research and from the perspective of nature and methodology, the study is conducted via the historical and descriptive-analytical method. The data collection method was library study and fieldwork. Initially, the political and religious figure of  Mehr-Narseh was analyzed and studied, with the help of the written sources related to him or the fire temples attributed to him, to reach understanding about the nature of his fire temples through a comparison between his character and the characteristics of the fire temples attributed to him. The next step was the archeological surveys in the fieldwork alongside the library researches and evaluating the archeological documents and reports about the proposed Chahar-Taqs for the location of the fire temples attributed to Mehr-Narseh, from an architectural perspective to finally reach a suitable point of view about the architectural and religious quality of the fire temples attributed to Mehr-Narseh.

Discussion
According to Pahlavi and Islamic sources, Mehr-Narseh, the minister of the Middle Sassanid period, has attained his highest religious official during the reign of Bahram V, as the honored titles of the servant of the two fire temples, since in the “Matigan-i Hazar Datistan” there is no mention of him being resented by Bahram V. During the reign of Yazdgerd II and Pirouz, he and his wife were sentenced to be the “Ādurwaxšīh” or tending the fire of the temple fire, due to a sin that some researchers associated with Zurvanism. The religious dedication of Mehr-Narseh resulted in the construction of several public buildings in the provinces of Ardashir-Khwarrah and Shapur –Khwarrah and also four religious temples on his ancestral lands for himself and his three sons, which were run by his heirs until the first centuries of Islamic period; these fire temples were shires dedicated to the “Atash-e Dadgah”. Based on the archeological findings and the presented theories, the remains of the three Chahar-Taq of “Malik”, “Tall-i Djangi”, and “Khurma yak” can be identical with one of the four fire temples belonging to Mehr-Narseh, as well as to match the information provided in written historical sources. Meanwhile, the site of “Pir-e Jeyran” may also be considered as the fourth fire temple of Mehr-Narseh in Abruwān. Based on the comparison studies of the archaeological evidence and the written sources, it can be concluded that during the Sassanid period, the shrines associated with the fire Dādgāh, could be very magnificent according to the financial conditions and social status of its founder and have donations such as gardens and farmland, and their revenues were spent for the happiness of the soul of the founder. Such fire temples were also run by a person named “Sallar” or the guardian who was chosen by the founder of the fire temple, and this responsibility was transferable to their heirs. The existence of such a title could indicate that other people also served in these private fire temples, and therefore this category of family fire temples, like the fire temples associated with the “Behrām” and “Ādarān” fires, could have hierarchical complexities in terms of the number of servers.

Conclusion
Based on the results of this study, it seems that the fire temples built by Mehr-Narseh included two separate types and four fire temples attriuted to him located in Abruwān area were related to family fire meaned “Dādgāh”. According to the field studies and similarity, the previous theories can be criticized and a new group of religious temple of Sasanian period in Farashband can be introduced that contains one or several fire temples, which are attributed to Mehr-Narseh. It seems that these kinds of fire temples have a complex plan with additional architectural and probably had a number of attendants to do the work related to the fire temple. Overall, this research can provide a correct understanding of the fire temples of “Dādgāh” Fire during the Sassanid period. This also provides a new grouping manner for such these temples and can be known as a pattern for reviewing of usage and religious value of other similar Chahar-Taqis. Before this, no specific structure for the fire temples related to the fire of “Dādgāh” in the Sassanid period, had been introduced, and the only available evidence was about the findings in “Tull-i Sifidak” which has a cruciform architectural space beside the residential context, as a sacred place for the fire. Based on conducted analyses of this study, it is possible to categorize the different types of religious architectural structures dedicated to the fire of “Dādgāh” into two groups: The first type was the buildings that include a cruciferous space attached to their residential section, that might have simpler procedures and endowments. The second type was complexes including Chahar-Taq and interconnected architectural spaces, which were probably built in the endowed properties of the fire temple, including gardens and agricultural lands, and belonged to people with high social ranks in the Sassanid society, such as Mehr-Narseh fire temples.

Abstract
A study on religious buildings related to fire such as fire temples and Chahar Taqis in the Sassanid era shows that different factors have been considered in constructing these monuments as an important place for religious and ritualistic ceremonies. One of these factors is deviation from north. In Avesta and other Pahlavi texts such as Vendidad, Khorde Avesta, Gozidaha-ye Zadesparm, Bundahish, Arda Viraf Nameh, Shayest Nashayest, and etc. north direction is the gateway to hell and a direction for Ahriman and the demons. According to this, and considering Avesta’s lack of clarity on temples and fire temples, the purpose of this study is to clarify how strongly religious, rituals and mythical matters have been considered in constructing fire temples. Aiming at answering the question: “Whether deviation from north and building worship places related to fire in ordinal directions, as well as placing interior elements of these worship places during the ceremonies not to face north are related to religious rituals or not?”, it has been tried to clarify the reasons of deviation from the north with a historical-analytical approach and based on archaeological evidence, compliance with Pahlavi texts and today’s Zoroastrian customs. Results of studying religious monuments in the Sassanid era show that, due to the belief of north being a direction for Ahriman and the demons in Zoroastrian rituals and Iranian myths, Mobads’ place during Zoroastrian ceremonies was of utmost importance. It had to avoid north. Also, the majority of the fire temples and palaces have been built in ordinal directions, or the main entrance to the building was built in any other direction except the north. Therefore, it can be assumed that some religious and ritualistic reasons are the reasons why the Sassanians paid extra attention to deviating from the north in building their religious monuments. 
Keywords: Fire Temple, North Direction, Apakhtar, Chahar Taqi, Sassanid Era. 

Introduction
The archaeological evidence indicates that many factors, including the construction of ordinal directions, were taken into account when constructing the fire-related monuments in the Sassanid era. Now, the main question is why should a fire temple or Chahar Taqi be built on ordinal directions? And basically, why it has been taken into account in all fire temples? To find the answer to this question, the religious and ritual texts of the Sassanid era and some of the Zoroastrian written sources can be helpful; thus, relying merely on archaeological evidence cannot answer all questions about religious monuments of the Sassanid era. Thus, achieving a comprehensive perspective in this regard necessitates finding a logical relationship between the archaeological evidence and the Zoroastrian written texts. The religious texts have pointed to the fact that the position of Ahriman and winter is the north direction or Apakhtar. Since Iranians assumed the north direction as the position of winter and had no enemy bigger than winter or north and also considered the coldness as the worst disaster, they likely tended to construct their major buildings in a direction that deviated from the north because this is an important point that had been taken into consideration in religious and ritual ceremonies in Zoroastrianism. By reviewing all of the groupings and classifications presented by researchers on the location and placement of the fire-related monuments across Iran, we can figure out that most of these monuments, either having a circumambulation or without it, either being isolated or being located at the villages or city centers, and either belonging to the early, mid, or late Sassanid era, have been built on ordinal directions, and the deviation-from-north pattern is observable in most of them. In the present work, the Authors attempt to investigate the reasons for the placement of the fire temples and Chahar Taqis on ordinal directions by using a descriptive-analytical method. For this purpose, initially, the religious texts such as Avesta, Vendidad, and other Zoroastrian texts are investigated through the documentary method. Then, relying on the archaeological evidence, the instances of deviation from the north in the fire temples are identified and introduced. On this basis, the fire temples and Chahar Taqis of the Sassanid era across Iran are investigated. Yet, the main analysis in this work is based on some newly found fire temples in the west of Iran, which have provided considerable evidence in this regard. 

Discussion 
Consider the Adur Gushnasp fire temple in Takht-e Suleiman as the criterion for the identification of the Sassanid fire temples architecture style, said that the influence of this type of building plan (especially deviation from the north) can be observed in other fire temples of this era. According to the explorations of the Sassanid fire temples in the west of Iran, most of them have some features in common, one of which is the deviation from north and construction on ordinal directions. For instance, among the three Shiyan, Mil-e Milegeh, and Palang Gerd fire temples, there are similarities in terms of the plan, material, firebases, T-shape platform, and deviation from the north. In Mil-e Milegeh and Palang Gerd, the T-shape platforms are placed between the northern piers while in the Shiyan fire temple; the T-shape platform is placed at the western gate. Despite various theories regarding the function of these platforms, the T-shape platforms have been placed in such a manner as to avoid facing the north while performing or watching the ceremonies. Considering the religious, political, and social changes occurring during the 3 several hundred years of the Sassanid dynasty, it is inferable that the plans of the religious buildings of the early, mid, and late Sassanid era exhibit some changes. However, the construction of religious buildings in ordinal directions is a factor that has been taken into consideration during the whole Sassanid dynasty without being changed. Based on the archaeological evidence we can observe the deviation from the north in the placement of the building of the temples, direction of the building’s entrance, and finally, the placement of the platforms in the interior space of the temples. Some of the reasons for considering the deviation from the north include the consideration of the ritual and mythical issues, the lethality of coldness in Iranian’s culture, confliction between the position of the Iranian and Indian Yazatas and demons, and a significant relationship between the direction and intensity of sunlight and its impact on the formation of spatial patterns of the constructions. 

Conclusion 
Although there is not sufficient information available regarding how the location for fire temples was selected, an investigation and comparison of the Avesta and Zoroastrian written sources with archaeological evidence indicates that some ritual aspects such as considering a deviation from the north have been probably an essential factor when constructing these monuments. The most obvious evidence for the consideration of the deviation from the north can be seen in Adur Gushnasp fire temple, the plan of which has been repeated in most of the fire temples of the Sassanid era, especially in fire temples of the west of Iran such as Shiyan, Mil-e Milegeh, and Palang Gerd. Since the direction to which the Mobads, individuals, and fire were facing has been very important in ritual ceremonies and other purification-related ceremonies, the construction of these monuments in a direction that deviated from the north might be attributed to the religious and mythical instructions. The comparison of the archaeological evidence with written Pahlavi sources and current Zoroastrian ceremonies indicates that the deviation from the north had been taken into consideration while selecting the temple locations, determining the building entrance directions, and the platform placement in the interior spaces of these locations.