In this survey, the symbolic motifs, which are used in the two stone monuments of Bisotoun and Taq-e-bostan, are examined and analyzed as visual media devoid of speech but possessing meaning. The main issue of this research is to examine the role of these symbols in transmitting cosmic, mythological, and religious concepts of ancient Iran and their impact on the formation of royal and cultural ideology.
       The common belief of human beings in ancient times was that transcendent and wise forces guided the destiny of mankind, and that unknown and superior forces were embodied in the form of gods and goddesses. The symbolic and imaginative images in the works of art of that era were manifestations of these heavenly and earthly forces, playing an effective role in the transmission of cultural ideas and beliefs among ancient civilizations.
       The art of iconography in Achaemenes of Iran included a set of powerful and meaningful symbols, many of which were first carved on the rocks of Mount Bisotoun by order of Darius I, inspired by the art of ancient Asian civilizations and combined with the artistic tradition of the Medes. After Alexander's invasion of Iran, some of the cultural and artistic characteristics of the Achaemenes underwent transformation.
       Over time, especially during the Parthian period, Iranian art distanced itself somewhat from the influence of Greek elements and gained an independent identity. However, the Sassanian Empire, who considered themselves the heirs of the Achaemenes, not only revived the art and culture of that period, but also brought it to its peak with new innovations.
       The Bisotoun and Taq-e-bostan stone monuments carved during the era of two great empires of ancient Iran have significant similarities, including the subject of pictorial narratives, geographical location, surrounding nature, and the sacredness of the Bisotoun and Parav mountains. The main aim of this research is to examine the similarities and differences in content and appearance of symbolic motifs in the two historical periods of Achaemenes and Sasanian and to explain the evolution of their visual language in the context of political and social developments in ancient Iran.
       This study was conducted to use a comparative analysis method and examine the conceptual continuity and discontinuity in the iconography of the two periods from the perspective of art history. The basic questions are:
1- How do the visual symbols in Bisotoun and Taq-e-bostan reflect the worldview and power structure of their era?
2- What visual elements were transferred or transformed from the period of Achaemenes to the period of Sasanian?
       The research hypothesis is that the change in symbolic language is a reflection of the identity and discourse developments of ancient Iran, and the art of petroglyphs carries historical concepts in the context of images.
       The results of the present study is to show that the symbolic motifs of Bisotoun and Taq-e-bostan, despite historical differences, have common roots and undergone changes in form, meaning, and function over time. This change includes the elimination and replacement of some specific symbols and the fixation of a number of visual elements of the Bisotoun petroglyphs in Taq-e-bostan.
       Also, the evolution in the representation of scenes of power and the emergence of combined symbols in the Sasanian period is considered a reflection of the ideological and cultural changes of that period.



Introduction
 The petroglyphs of Bisotoun and Taq-e-bostan, as two significant works in the history of ancient Iranian art, are not only geographically adjacent to each other and in the heart of the Zagros Mountains, but also conceptually carry common themes reflecting the power structure, belief system, and political worldview of the eras of Achaemenes and Sasanian period. The location of these two monuments on the Silk Road and their location on the slopes of the sacred mountains of Bisotoun and Parav indicate a conscious choice of places with spiritual and symbolic significance that served to convey political and religious messages.
       In both works, the theme of granting royal legitimacy by a god or gods and the demonstration of victory over enemies, as central elements of the visual narrative, play the propaganda and ideological role. These themes have represented manifestations of courtly splendor, hunting, and music in different ways, in Bisotoun by emphasizing imperial order, and in Taq-e-bostan by creating royal scenes and gatherings. In addition, the presence of Zoroastrian religious symbols such as Ahoura Mazda, Mehr, and Anahita in both collections indicates the deep connection between religion and political power in ancient Iranian petroglyph art.
       The evolution of the visual language in these works, utilizing the artistic traditions of the Medes and indigenous peoples, reflects the continuity and evolution of Iranian iconography. In spite of the time gap of about thousand years between these two monuments, the common themes and similar symbolic structures are evidence of the continuity of cultural and cosmic concepts in official Iranian art.
       Despite numerous studies in the field of symbology and visual analysis of ancient works, there is a significant gap in comparative studies between petroglyphs from two different historical periods; especially in examining conceptual continuities and the evolution of visual language over time.
       The present study, focusing on the two monuments of Bisotoun and Taq-e-bostan, seeks to fill this gap and attempts to achieve a deep understanding of the semantic, symbolic, and pictorial structure in ancient art through an analytical and comparative approach. This study not only demonstrates the continuity of artistic traditions, but also reveals the evolution in pictorial expression and the political and religious functions of art.
 
Research Method
In this research, the method of comparative discussion and analysis with an art history approach has been used. The aim is to examine and compare symbolic motifs in the two stone monuments of Bisotoun and Taq-e-bostan in order to discover visual, conceptual and functional continuities, discontinuities and developments in the historical context of ancient Iran.
 
The research Steps are as Follows:
1- Definition of theoretical concepts and analytical framework,
       Key concepts such as symbol, visual language, royal ideology, and ritual art are explained, and theoretical foundations related to iconography and art history are examined,
2- Selection of visual examples from each monument,
       Key motifs such as the ring of power, the crown, the figure of Ahoura Mazda, symbols of winged angels, and the scenes of "coronation" and "stepping on the vanquished enemy" were chosen to cover temporal and formal diversity.
 
Discussion and Rationale of Analysis
In this study, the discussion and analysis is based on identifying the common and distinctive elements of two prominent works, Bisotoun and Taq-e-bostan, both of which are located in a similar geographical and spiritual context, and the theme of royal legitimacy and victory over enemies is prominent in them. The figure of “stepping on the chest of the defeated enemy” is a clear and vivid example of the continuity of a symbolic tradition that has continued from the Naramsin and Anubanini to the Achaemenes and Sassanians.
       By analyzing the context and discourse of the works in these two stone monuments, the role of symbols in representing power, legitimacy, sanctity, and national identity becomes clear.
The figure of “stepping on the chest of the defeated enemy” is a clear and vivid example of the continuity of a symbolic tradition that has continued from the Naramsin and Anubani to the Achaemenes and Sassanian Empire.
       By analyzing the context and discourse of the works in these two stone monuments, the role of symbols in representing power, legitimacy, sanctity, and national identity becomes clear.
The logic of comparative analysis requires that the historical and political context of both works first clarified, then similar visual elements identified, and finally their different functions in political and belief systems examined. In this way, the discussion and analysis not only reveals the continuity of artistic traditions but also shows the evolution in the political and religious functions of art.
       The discussion method in this research has been tried to be systematic based on visual evidence, historical texts, and references to reliable sources, in order to go beyond the level of description and achieve a deep understanding of the semantic and symbolic structure.
Finally, the stages of discussion and comparative analysis of this research are based on these four axes:
- Selecting common elements for comparison,
- Examining the formal, content, and contextual characteristics of each work,
- Analyzing differences and similarities in historical, cultural, and political context,
- Discovering trends in artistic evolution, influence, or independence.
 
Conclusion
The two stone monuments of Bisotoun and Taq-e-bostan, located in the Zagros Mountains, are outstanding examples of the interaction between nature, history, and political power in ancient Iran. These works are not only valuable historical documents from the Achaemenes and Sasanian periods, but also reflect conceptual and aesthetic developments in royal and ritual iconography.
       A comparative analysis of the pictorial symbols in these two monuments shows that many of the symbolic motifs, despite their temporal and cultural differences, have common roots and have undergone changes in form, meaning, and function over time. These changes can be classified into five main categories:
1. Unique Symbols of the Darius Period in Bisotoun:
Symbols such as the horned helmet of Ahoura Mazda or the star of Ishtar, which, due to changes in political and cultural attitudes, were not repeated in later works of the Achaemenes and were replaced by more Iranian symbols such as the Persian helmet and the solar rose.
2. Symbols Fixed in Form and Meaning:
       Symbols such as the ring of power, the rimmed crown, and the scene of the king's victory over the enemy, which have been repeated from Bisotoun to Taq-e-bostan without any fundamental changes in form or meaning.
3. Symbols with Visual Evolution and Preservation of Meaning:
       Like the winged figure of Ahoura Mazda, represented in Bisotoun as an abstract divine symbol and in Taq-e-bostan in a more human form, but retains the concept of holiness and legitimacy.
4. Symbols with Evolution in Form and Function:
       Such as the change in the symbol of the weapon from the bow in the hand of Darius I to the sword in the hands of the Sasanian kings indicating a change in the depiction of military power.
5. Emerging and Integrated Symbols in the Sasanian Period:
       Symbols such as the wavy bands (diadems) and winged angels, influenced by Greek art and Parthian tradition and localized by Zoroastrian beliefs, are prominent in Taqebostan as symbols of glory, victory, and freedom.