Abstract
The ancient site of Natel is located in the village of Natel Kenar-e Olia, a district of the city of Nour, which is 6 kilometers southwest of this city in the west of Mazandaran province. According to historical written sources, this city was considered as one of the important cities in Tabaristan during the Abbasid period and had a military garrison. Due to the importance of this historical site, in addition to archaeological surveys, three excavations have been carried out in this site so far in 2008, 2010, and 2016 under the supervision of Abdolreza Mohajerinejad. The present study focuses on some pottery findings of the first and second seasons of these excavations, during which 2166 pieces of glazed and non-glazed pottery were obtained among other findings. Chronology of the aforementioned samples and consequently more detailed and precise knowledge of the settlement periods, better and greater recognition of the pottery of this site, in particular, and pottery of the Islamic period in the southern margin of the Mazandaran Sea, in general, awareness of the similarity and differences of the pottery obtained from this site with the major pottery centers of the Islamic era required a thorough and in-depth study of these samples in the form of classification, typology, and a typological comparison that was carried out in this research. The results of this study show that most of the studied samples belong to the early (3 and 4 AH) and mid-Islamic (5 and 9 AH) centuries, while the samples of the Ilkhanid and Timurid period in this collection are much lower in number than those of the previous centuries. Also, the results of statistical studies on pottery of the historical town of Natel indicate that these pottery wares have relatively good production quality and strength, but they have a lower level in terms of manufacturing technique and diversity of motifs. 
Keywords: Natel, Islamic Pottery, Classification, Typology, Typological Comparison.

Introduction
The ancient site of Natel is located in the village of Natel Kenar-e Olia, a district of the city of Nour, which is 6 kilometers southwest of this city in the west of Mazandaran province. Given the importance of this site in the Islamic period of Iran, especially the southern margin of the Mazandaran Sea, the first scientific studies to identify and determine the location of this town were carried out by Abdolreza Mohajerinejad in 2006 during a season of a survey (Mohajerinejad et al., 2017: 247) and then these studies were continued under his supervision during three seasons of excavation in 2008, 2010, 2016 (Mohajerinejad, 2008; ibid, 2010; ibid, 2016). During the first and second seasons of the excavation, along with other findings, 2166 pieces of pottery were discovered which were provided to the authors for further investigations. Therefore, during the classification and typology stages, 235 indicative pottery types were selected and excluded from the collection. To advance the research, the authors selected and studied 50 pieces from among the indicative samples selected from among the collection based on the non-repetitive variable. Due to the diversity and multiplicity of the pottery types and for better identification of the pottery of this site in particular and the pottery of the southern coastal areas of the Mazandaran Sea in general, the similarity and differences of pottery obtained from this site with those of the major pottery centers of the Islamic era, and also to gain more accurate knowledge of the settlement periods of the site, it was necessary to study the pottery samples very carefully. Accordingly, the present study seeks to answer the research questions through recording, registering, classifying, typology, and typological comparison of these pottery collections (2149 fragments belonged to the first season and 67 fragments belonged to the second season). The most important questions this research seeks to answer through scientific and systematic studies are: 1: to which period or periods do the pottery samples discovered in the historic town of Natel belong? 2: how is the status of the pottery samples discovered from the historic town of Natel, in terms of production quality and decorations compared to the major pottery centers of Iran during the Islamic era? In answer to the first question, it should be noted that the pottery discovered from the first and second seasons of excavation in the Natel historical site belongs to a time period extending from the early Islamic centuries to the Timurid era. And the answer to the second question is as follows: the production quality of the Natel pottery as well as the decorative quality of Sgraffito pottery are similar to those of the major Iranian pottery centers, but other pottery samples obtained from Natel are in a lower level in terms of their decorative quality, especially in color painting. 

A Summary of the Paper
Initially, the samples were classified according to two variables, i.e. their coating type and being simple or painted, which are divided into four groups: non-glazed simple pottery, non-glazed painted pottery, glazed simple pottery, and glazed painted pottery. Then, at the typology stage within the classification framework, each group of pottery was classified into several types and sub-types according to one or more variables. The investigations were carried out with great sensitivity and accuracy and finally, this resulted in the typology of the pottery in the form of 45 types and sub-types. Statistical studies on the ceramics of this collection indicated that the glazed simple pottery was the most frequent type among all the groups with a frequency of 46.53%. Overall, these ceramics have relatively good production quality and strength, but the glazed painted ceramics are at a lower level in terms of production technique and variety of motifs. The non-glazed painted pottery pieces in this collection have geometric motifs and the dominant motif type in this group is ripple motif in terms of motif design variable. At the typological comparison stage of classification which has been carried out according to the classification and typology of pottery collection, it was attempted to compare a large number of fragments with pottery found in Islamic sites. Therefore, in addition to reviewing various reports of excavations carried out in Islamic sites (generally, the northern sites of the country are considered), we have carefully studied the authentic sources of Islamic pottery prepared and organized by the efforts of foreign and domestic scholars and accordingly the pottery types, which were compared with similar example or examples, were dated and the comparisons are presented in the form of tables in the main text of the paper. From among the regions or sites whose ceramics are comparable to those of the Islamic period of Natel, Bamiyan, Nishabur, Jorjan, Poinak castle of Varamin, Imam Zadeh Ali Lafourak in Savadkouh, Sarqala of Lavasan, Sheikh Safieddin Ardebil’s tomb, Sistan, Golkhandan fortress, Kaseh al-Mout, Gaskar site of Gilan, Haft Daghnan of Gilan, northwest of Iran, Osbou Kola Lofer, and Jahan Nama site can be mentioned. 

Conclusion 
According to the contents of the present study as well as the classification, typology, and typological comparison of the pottery discovered from the historic town of Natel, it can be stated that there are a total of 45 different ceramic types and subtypes in this collection. The results of typological comparisons of the pottery of the Islamic period of Natel showed this collection had the highest rate of similarity and relationship with the pottery obtained from the sites of the Islamic period in the north of the country; this cultural and artistic similarity supports the existence of a wide cultural and connection network between Natel and its neighboring regions and indicates the production and expansion of formal and standard pottery types during different Islamic times that were produced in specific centers and exported to other regions. Their production techniques were imitated in local workshops with a lower quality. In general, the results of this study suggest that most of the studied samples belong to the early (3 and 4 AH) and mid-Islamic (5 and 9 AH) centuries. The results of the statistical studies on the pottery of Natel also indicate that these pottery findings have a relatively good production quality, but they are at a lower level in terms of production technique and diversity of motifs.  

Bibi Doost Tepe series around Bonjar city of the central part of Zabol city in the north of Sistan and Baluchistan province along the Niyatak channel in a north-south direction. These series of Tepe due to its Massive volume of cultural materials, especially pottery samples and the proximity to the Zahedan Kohne site the second government House of Sistan in the Islamic era it is of special importance in the Studies of Archaeology and History of Sistan, accordingly with the issuance of a license from the Archaeological Research Institute in 2016, speculation to determine the area and privacy done. In this study 877 pieces of pottery related to the Islamic era were identified, recorded and studied. Examples mentioned in four groups: Simple unglazed pottery, no engraved glaze, Simple glazed and Glazed engraved were located. in this research an attempt was made to start Study ancient sources and Archaeological Researches the Real Identity of Bibi Doost Tepe in the North of Zahedan Kohne Then, the samples of pottery collected from the level of Bibi Doost Tepe should be applied to: their typology and relative dating. The results of the studies indicate that it is important that the Bibi Doost Tepe are part of the second capital of Sistan due to its location in the area of Zahedan Kohne. And the results of the study conducted on its pottery also informs about the technique of making high quality pottery in the Islamic era, in the north of Sistan plain. The results of the studies also clearly show the cultural connection of this region with the Baluchistan basins of Iran and Afghanistan, Greater Khorasan, Kerman, Central Plateau and parts of Central Asia. The present study intends to provide a ground for illuminating a part of the Islamic era of Sistan by conducting a scientific and methodical study.
Keywords: Sistan, Bibi Doost Tepe Series, Pottery Of The Islamic Period, Reading Ancient Sources, Typological Comparison.   

Introduction
Sistan and Baluchistan province with an area of about 187,502 square kilometers is equivalent to 9.1% of the area of Iran, of which 8,117 kilometers are related to the Sistan region (Najjar Salighe, 2015: 25). Citing historical sources, there is no doubt that the land of Sistan had great importance and capabilities during the Islamic era. The site of Bibi Doost, in the form of a series of continuous Tepe on the western edge and along the Niyatak channel in the north of Zabol city, in the north of Sistan region, at an altitude of 493 meters above sea level and in the geographical position N: 3106740 and E:6136897 can be seen. Considering the proximity of this series of Tepe to the Zahedan Kohne area, a systematic archaeological investigation of the Bibi Doost area with the aim of determining the identity of these Tepe, discovering the history of settlement, types of pottery and how it has cultural relations with other Neighboring points were put on the agenda and efforts were made to provide appropriate answers to existing questions by conducting scientific studies on the collected terracotta samples and reading ancient sources.
Research method: The research method in this research is descriptive, comparative-analytical. which is based on two parts of field investigations and the use of library resources. The field method in this research is that after preparing and drawing the topographical map of the region, which includes an area of about 30 square kilometers, by 8 experts in a step-by-step survey, compacted at distances of 50 meters from each other. It has been surveyed that during this survey, 877 pieces of pottery related to the Islamic era were identified, collected, recorded and studied from all the existing structures. In addition, the sampling process, which was considered the most important part of the field method, was done randomly and categorized by indicators.
Research questions: 1) Based on the reading of the ancient sources and the study of the pottery of the Bibi Doost hill series, can this area be considered a part of the ancient city of Zahedan Kohne? 2) What types of pottery from the Islamic era can be identified in the Bibi Doost hill range? 3) In what time period are the studied pottery findings dated? 4. Based on the pottery findings, how are its regional and extra-regional connections evaluated?

Discussion
In this research, an effort was made to study the distribution of ancient structures in the Bibi Doost area and their proximity to the Zahedan Kohne area in accordance with the predetermined goals. Due to the extensive destruction of Zahedan Kohne city and the change of its cultural and ancient landscape, an effort was made to use ancient sources and archeological finds (potteries) in order to know its exact extent. In the first part of the research, based on the reading of ancient sources, it was determined that the series of Tepe of Bibi Doost is a wide area of ancient monuments, which is completely different from the point of view of the types of pottery, the date of settlement, the type and structure of the structures and the references of the texts. It can be mentioned as part of the old books of Rabaz city Zahedan Kohne, the second Government House of Sistan (Kiekha, 2016: 1120-1120). For example, Qasim-Abad mill or Kusang mill, which is probably the minaret of the mosque or the caravanserai mill in the area of Zahedan Kohne city Rabd (Landour, 1999: 635 & 652), is currently among the ancient monuments of the Tepe dynasty. It is located in the center of Bibi Doost, which indicates that the scattered structures in the Bibi Doost area are in full connection with the Zahedan Kohne area. In the continuation of the research and in order to answer other questions, it was tried to study and investigate the types of terracotta in the Bibi Doost hill range. Regarding the classification and typology of the pottery of the Islamic era of the Bibi Doost Tepe series, which led to the identification of more than 18 types and subspecies of pottery, it shows that the potters of Sistan used various methods of production. and the decoration of pottery of the Islamic era. Then, the pottery samples of Bibi Doost area, which are considered the most important documents for the chronology of this area, were compared with the samples and pottery vessels found in the explored and investigated areas. they got. The results of the studies of the samples and the comparisons show that the pottery of the Bibi Doost hill series in the middle centuries of Islam (4 and 5 to 9 centuries A.H.) can be dated. are set This importance is completely consistent with the rise and fall of the Sistan plain and its centrality at that time, which is the city of Zahedan Kohne. In the end, the results of the typological comparisons of the pottery samples of the Bibi Doost area clearly show the similarity of these samples with the pottery of the neighboring areas, especially Khorasan.

Conclusion
Studying the architectural structures scattered in the Bibi Doost hill range, at first glance, due to the high amount of destruction, their identification and connection with the Zahedan Kohne area was almost impossible. Therefore, an effort was made to identify the true identity of these Tepe by reading ancient texts and studying the surface pottery of this area. Taking into account the different parts of the city of Zahedan Kohne that were known earlier (five separate parts called the Castle or fortress, the first citadel, the second citadel, Sharstan and Rabd), now we can The chain of Tepe known as Bibi Doost, which is located in the vicinity of the northwest front of the city of Zahedan Kohne, added a part of the Rabd of this city, which is the second Government House of Sistan. The collection of historical evidences about the foundation and decline of the city of Zahedan Kohne in the Islamic era shows that this city was founded in the 4th and 5th centuries of AH and started to decline in the 9th century of AH. The study of the pottery of the Bibi Doost hill series also confirms the same point. Based on the study of the pottery, the oldest type of pottery in the area is dated to the 4th and 5th centuries of AH and the most recent one is dated to the 9th century of AH, which is completely consistent with the rise and fall. It is located in the city of Zahedan Kohne and another reason is that this series of Tepe is part of the main structure of the city of Zahedan Kohne.