An Investigation of the Implications of the Circle Motif in the Decorations of Ilkhanid Buildings

Introduction
After the establishment of the Ilkhanid dynasty, the Ilkhan's interest in Iranian culture and art led to the emergence of a new approach in the arts of Iran. Add to this, the influence of the ruling tribe's beliefs and culture on artists. This era witnessed distinctive changes in architecture not only in terms of design and construction but also in decorative elements. Geometric motifs were among the most commonly used motifs in architectural decoration as they had the capacity to create a wide variety of compositions. The circle was among the fundamental geometric motifs that embodied multiple meanings and was closely associated with religions and religious beliefs. In this research, the motif of circle in the architectural decorations of several Ilkhanid monuments, including the tomb of Abd al-Samad Natanzi, the tomb of Seyed Rokn al-Din and Seyed Shams al-Din in Yazd, Oshtorjan Mosque were examined. Based on observations and investigations, this motif was found to appear exclusively in the buildings of this era.
 
Research Method
This research deployed a descriptive- analytic method, using library documents and field observations with a semiotic approach. Since Charles Sanders Peirce's classification is best known for elucidating the "different modes of relationship" between a sign and its object, this study used Peirce's tripartite model and separated the concepts of the circle motif and analyzed it. there are three types of signs in Peirce's framework: first includes analogies or icons, which create images of things only through their visual imitation; second refers to indicators or indices that indicate thing through physical connection to them, and third is concerned with symbols or common signs that are linked to meanings through use and a conventional relationship Due to the presence of the circle motif in diverse structures, especially in the doorway of the building, this research aimed to discuss the reasons behind the frequent use of the circle motif in combination with other decorative motifs, and inscriptions. It also aimed to seek its implications as used merely in Ilkhanid buildings, especially tombs and to identify its symbolic meaning and its relationship with the changing religious structure of the Mongol Sultans. This study tried to answer this question: what was the reason for using the circle motif, especially in decorating the doorways of some Ilkhanid building? The initial assumption was that the circle motif was one of the main bases for designing geometric motifs for decoration in the post-Islamic era, including a combination of various religious and cultural meanings.
 
Findings and Results
The circle motif, which in some Ilkhanid buildings acquired a delicacy of "Shamseh" had all three referential dimensions of the sign in Peirce's framework. In its visual manifestation, the circle represented celestial bodies, especially the sun and the moon, which were considered God in religious beliefs since the beginning of human civilization. Over time, the sun was recognized as the observing eye of the sky God, and the circle became a symbol of both the sky and the sun. Due to its circular form, which had no beginning or end, the circle became a symbol of the repeatable structure of time and the infinity of the universe. In mystical beliefs such as Buddhism and Islamic Sufism, the cycles of time and life, depicted as the combination of concentric circles, implied the stages of man's journey towards spirituality and ultimate tranquility in the presence of the Creator. These concepts were mixed with the early religious beliefs of the Mongols, namely Shamanism and Buddhism along with Islam and Sufi Ideas later. As a result, symbolic motifs were used in different ways in the decoration of buildings from this period. A motif such as the circle, despite the very old in the history of human culture and art, was used in this period in pair in the doorways of buildings (related to religion and Sufism) or as a dominant motif in the walls and crescents under the doorways. Its usage was in a way that in previous and subsequent periods this kind of combination of the circle motif was not observed in the decoration of buildings.
Conclusion
The following results, obtained from this research, clarify the special use of circle motif in the doorway and dome chamber of tombs built during the Mongol Ilkhanid era in Iran:

The earliest groups of Mongols under the leadership of Genghis Khan practiced shamanistic beliefs and considered Genghis as the embodiment of the sky god. A number of Ilkhanid sultans were Buddhists and considered circles and mandalas as the most important symbolic motifs of Buddhism--reflecting the cycle of life and the hierarchy of achieving spirituality and spiritual ascension. It was figured out that the usage of sun-shaped circle in these buildings was related to the conversion of leading sultans including Ghazan Khan and Oljaitu to Islam, to the presence of the circle in Islamic decorations, to popular Sufism at the time since it was used to decorate the tombs of the elders Sufists and their Khanqahs.
In the path of Islamic mysticism and Sufism, the circle was considered the compass point of existence and the unity of presence; hence the special use of this motif in the tombs of Sufi and Shiite Sheikhs was explained.
Moreover, the relationship of the circle with the sky and the protective, watchful eye of the God/gods demonstrated a cultural interaction between the early, ancient beliefs of the Mongols and their religious practices after conversion to Islam and Sufism.
Finally, the pair of circles used at the entrance of the building was considered a symbol of the spiritual power of the sky and a repellent of the filth and evil, a protector protecting the people of the Khanqah and the soul of the owner of the tomb from evil.