Abstract
Chehelsotoun Palace has always been a source of traditional and new interventions in the restoration of murals, which indicates the evolution of views on this issue in Iran. This study aims to understand the evolution of conservation and restoration approaches to murals by referring to the tradition of previous repairs and new approaches to conservation and restoration has studied murals in Chehelsotoun Palace and has sought to answer these questions: What were the procedures of the previous repair tradition? What were the new approaches to the conservation and restoration of murals and their fundamentals? What were the differences between the two? Data collection was done by documentary method. First, by adopting a comparative and descriptive method, the previous repairs will be examined. Then, the research, which has a qualitative and interpretive approach, uses an analytical method to explain the issues about the tradition of previous repairs and the fundamentals of new approaches. In the end, the results will be explained with logical reasoning. The research findings indicate that the previous repairs were performed in the form of repainting on the original murals, in the continuation of the life of Iranian Traditional Paintings. Such repainting, while following the visual elements of the original murals, also has different expressions from the artist in charge of the repair, which was rooted in the tradition of previous mural repairs and their contexts. New approaches were based on historical authenticity and aesthetic integrity, and led to the removal of some of the stages of mural development and reintegrated of the lacunas with a distinction from the original murals. The aesthetic and historiographical approaches of the West were the source of the differences between the new interventions and the semantic procedures of traditional repair which always focused on the nature of things. 
Keywords: Repair Tradition, Conservation and Restoration Approaches, Mural, Chehelsotoun, IsMEO Group.

Introduction
In recent years, the need to pay attention to the tradition of indigenous conservation in accordance with the specific cultural, intellectual, religious, historical and social contexts of each land; has been considered by international forums. In Iran, there are still many points about the tradition of heritage protection and repair that need researched and will cause to be known, like Western societies, the origins and evolution of views, procedures and approaches in the field of conservation and restoration in Iran. Chehelsotoun Palace murals have always been the subject of a variety of interventions, from previous repairs to new conservation and restoration approaches that became common in the mid-1940s. Today, only a few traces of the previous procedures of repairing murals in Iran have been left. In particular, the undesirable evaluation of traditional repair procedures has left no opportunity for their recognition. While in international treaties and documents have always been emphasized the importance of indigenous conservation traditions in each region and the role of recognizing these traditions as an intangible aspect of heritage in its preservation has been considered important. On the other hand, despite the continuation of many new approaches to the conservation and restoration of murals those took place in the mid-1940s; their constructive principles and criteria, and how they deal with previous procedures, have not been studied. This study will also explore the tradition of previous repairs to some of Chehelsotoun murals and how they were transformed into new conservation principles.
The aim of the present study is to gain an understanding of the tradition of previous repairs and the foundations of new approaches to conservation and restoration in Chehelsotoun murals, and finally an analytical cognition of how they differ from each other.
In conducting the research, the following questions were considered: What were the procedures of the previous repair tradition? What were the new approaches to the conservation and restoration of murals and their fundamentals? What were the differences between the two? Data collection was done by documentary method. First, by adopting a comparative and descriptive method, the previous repairs will be examined. Then, the research, which has a qualitative and interpretive approach, uses an analytical method to explain the issues about the tradition of previous repairs and the fundamentals of new approaches. In the end, the results will be explained with logical reasoning.

Discussion
In previous procedures, the purpose of the artist in charge of repair was to Continuing the spiritual dimension of the heritage. The artist performed traditional repairs according to the moral, intellectual and spiritual functions that traditional art had given him. Such repairs to the murals in question took the form of repainting performed by the artist directly on the original mural. These repainting, while having visual elements and general similarities with the original murals, also displayed different expressions from the artist in charge of the repair. The traditional repairs in imitation of the original murals, along with different expressions from the artist in charge of the repair, were a kind of mimesis of the original murals, as a representation of the original mural through the wishes, thoughts and ideology of the artist in charge of the repair. Also, the process of traditional repairs of murals had a hierarchy in the tradition of teaching art techniques. Such repairs, in the midst of the prevalence of the eclectic style of Qajar painting and then the abandonment of past traditions and covenants, were a kind of revival of the themes and features of traditional painting in the form of murals.
Restoring the Safavid identity and recovering the older layers of the murals was one of the main approaches of the new currents of conservation and restoration in Chehelsotoun Palace, As the IsMEO group seldom left evidence of traditional repairs on murals. IsMEO also used a system recognizable of distinct restorative additions to older sections in order to avoid misleading restoration operations in addition to establishing aesthetic integrity. Following the emphasis on preserving all the remains of the surviving murals from the Safavid period, the treatment of the murals with strategies resulting from the application of science gained a lot of importance. Thus, the use of new materials to help materials that no longer had the desired function, found a new place in the conservation and restoration of murals in Iran. It should be noted, however, that with the exception of a few experiments, the results of an accurate assessment of the compatibility between such solutions and the main materials of the murals and the traditional methods of their construction have not been published by IsMEO.

Conclusion
The new approaches to the preservation and restoration of the murals discussed at Chehelsotoun were based on an assessment of the aesthetic and historical aspects of the murals. IsMEO’s methods for reintegrating the lacunas of murals were also linked to the two fundamental categories of the historical authenticity and artistic integrity of murals. Aesthetic approaches in the new currents of conservation and restoration, derived from the perspective of art for art and beauty in a pleasant and enjoyable sense. Following this view; Attention to the main intention of the artist, and subjectivity, found a special place in many approaches to conservation and restoration. In contrast, traditional repairs were semantic in nature rather than aesthetic in appearance. Previous procedures were subject to spiritual concepts and also used visual values to express spiritual and epistemological expressions.
Emphasis on the historical authenticity in new currents was another way of distinguishing it from previous procedures. This view arose following the disintegration of Western societies from the past and the formation of historical consciousness, and forbade the process of re-creation and competition with the original artist in restoration. But in contrast to the new approaches focused on the nature of things and their semantic and epistemological aspects, they were independent of the time and place of the phenomena.