Features and Function of the Stone Staircase at Qal’eh Sang in Sirjan Based on the Archaeological Excavations and Historical Sources

Abstract
The old city of Sirjan developed during the 11th – 15th centuries in the Qal’eh Sang near the modern city of Sirjan. There is a limestone staircase with an inscription on the northern slope of Qaleh Sang. Various hypotheses have been made about its function, such as a Minbar or pulpit for a mosque from the Muzaffarids period, or an artifact related to the fire-altar. In the excavation at the Qal’eh Sang in 2015 new information was obtained about the staircase that is important for evaluating previous hypotheses. The question is what was the process of formation, changes, and functions of the stone staircase in the Qal’eh Sang? This paper deals with the results of the excavation at Qal’eh Sang and the study of historical sources. The results show that this artifact was not a staircase form before 789 AH/1387 CE. Therefore, it did not resemble the stone stairs of the fire-altar in Pasargadae. An inscription was first created on this artifact in 789 AH/1387 CE, and then its stairs were carved. Furthermore, no evidence of the mosque was found in the excavation around the staircase. Therefore, it was not an insitu Minbar or Pulpit. The north slope of Qal’eh Sang lay outside the Gate and was, therefore, on the outskirts of the city. This area has become a hewing workshop after the decline of the city. This stone artifact was probably made as a memorial to Sultan Ahmad, the Muzafarri ruler. It seems that the carving process of the Minbar was still in progress after the Timur’s invasion, but was never completed.  
Keywords: Qal’eh Sang, Stone Minbar, Stone Hewing, The Art of Muzaffarids, Archaeology of Sirjan.
Introduction
The old city of Sirjan was a strategic city between Kerman and Fars during the Islamic era. The position of this city as the capital of Kerman had made it important in the early Islamic centuries. After that, Sirjan maintained its importance as a focal point on the northern roads of the Persian Gulf (Amirhajloo and Sedighian, 2020: 1). 
According to archeological evidence and historical sources, the city of Sirjan was developed in Qal’eh Sang - 8 km southeast of the modern city of Sirjan - during the 5th to 9th centuries AH/11th -15th centuries AD (Afzal al-Din Kermani, 1947: 426; Monshi Kermani, 1949: 84-85; Mustawfi, 2009: 201). One of the most characteristic cultural materials on the northern slope of the Qal’eh Sang is a stone staircase with inscriptions.
The Research Question is as Follows: What was the process of formation, changes, and functions of the stone staircase in the Qal’eh Sang? Accordingly, in the archaeological excavation in the Qal’eh Sang, one of the three trenches was selected around the stone staircase. Analyzes about the process of making and function of the staircase were presented by matching the data obtained from historical sources, the technical study of the staircase, its inscriptions, and findings of the excavation in Trench I. 
Archaeological Studies
The main parts of the old city of Sirjan are formed in the east, south, and west of Qaleh Sang. The main gate of the city is located in the northeast. There are also architectural evidence and remains on the northern slope, but this section of Qal’eh Sang was outside the city, according to archeological evidence (Amirhajloo and Sedighian, 2020). The stone staircase is located on the northern slope of the Qal’eh Sang.
This staircase is made of white limestone in the shape of a vertical trapezoid with a height of 210 cm, a base of 276 cm, a chord of 290 cm, and a total width of 100 cm. On the southern body of the stone staircase, an inscription is engraved in one vertical and five horizontal rectangular frames. The upper part of the vertical frame is cut due to the creation of stairs. The inscription of the top frame is almost blurred, but the inscription of the other four horizontal frames from top to bottom is as follows: 
“The righteous king, the victorious from heaven, with a valuable and obvious victory, the pillar of truth and religion, trusting in the needless God through his good deeds, Sultan Ahmad, whose Authority was immortalized by God”. At the bottom of the frame, the phrase “The least servants of the Sultan...” is mentioned. The inscription of the vertical frame also indicates the date of the work: “In Jumada (?) Al-Ula of the year 789 Ah”. Emad al-Din Ahmad ruled in Kerman from 786 AH to 795 AH as a Muzaffarid Sultan after his brother, Shah Shoja (Basworth, 2002: 506; Qazvini, 2007: 198).
Discussion
Archaeological excavations around the stone staircase identified brick and clay walls, carved stone scraps, pottery pieces, and other small objects. The excavated architecture does not have a symmetrical plan and a regular structure. No signs of the Shabistan (mosque nave) and other spaces of a mosque were identified in this excavation. The relative chronology of the ceramics indicates that this part belongs to the fifth to early ninth century AH (Amirhajloo and Sedighian, 2020). Furthermore, the area around the stone staircase was a part of the city on the way to the main gate. But when the staircase was turned into a pulpit, it was turned into a workshop outside the city.
Varjavand believed that this artifact was a staircase of fire-altar from pre-Islamic times (Varjavand, 1972: 112). But Varjavand’s hypothesis is criticized. Because the inscription was carved earlier than the cutting of the stairs. This means that it did not have a stair shape at first, but had an inscription from 789 AH. Later, when the stairs were carved, the upper part of the vertical inscription was destroyed. The second critique is that there is no evidence from the Achaemenid to the Sassanid period around the Qal’eh Sang up to fifty kilometers (see: Hatami, 1995; Varjavand, 1972; Amirhajloo, 2015; Morgan and Leatherby, 1987; Sykes, 1902). Furthermore, it seems that this staircase was not moved from a historical site further away to the Qal’eh Sang. Because, it was not logical to move this heavy staircase from another place to the Qal’eh Sang, while there is an abundant source of stone in the center of the Qal’eh Sang. Secondly, the material of the rocks in the center of the city and those of the stairs is completely the same (sedimentary limestone).
Based on archaeological and historical evidence, it is suggested that this staircase was made as “a memorial or propaganda object, or a symbol of the legitimacy and power of the sultan”. Then its function was changed to the pulpit. There are several reasons for this suggestion:
First, the position of Emad al-Din Ahmad in Kerman and his influence on the rulers and deputies of the subordinate provinces, including Sirjan.
Second, the efforts of Emad al-Din Ahmad to strengthen the foundations of government and the continuation of legitimacy after 786 AH (the time of the death of the Shah Shoja).
Third, the efforts of his supporters to keep his name.
Fourth, the independence of the staircase from architectural structures.
Conclusion
The staircase of Qal’eh Sang did not resemble the stone stairs of the fire-altar in Pasargadae, because it was not a staircase from before 789 AH/1387 CE. An inscription was first created on this artifact in 789 AH/1387 CE, and then its stairs were carved. Furthermore, no evidence of the mosque was found in the excavation around the staircase. The north slope of Qal’eh Sang lay outside the Gate and was, therefore, on the outskirts of the city. This area has become a hewing workshop after the decline of the city. This stone artifact was probably made as a memorial to Sultan Ahmad, the Muzafarri ruler. The function of this object seems to have changed to the staircase or pulpit after the invasion of Timur. The carving process was still in progress after Timur’s invasion but was never completed.