Calligraphy in Iranian art and architecture is considered a significant decorative source for buildings and is more prominent in historical monuments. In the past, our country, Iran, had skilled calligraphers who, with their knowledge and awareness, were able to create inscriptions and decorations using various lines that have been the source of artistic and architectural development. This includes religious places such as mosques, which were the center of public gatherings and the place of observation for artists and rulers. The inscriptions on the main porch of the grand mosques, which are often in front of the dome, have always attracted the attention of painters and calligraphers throughout history. They have bestowed an aura of holiness and spirituality on these buildings, and have been a turning point in the presentation of their art and creativity. The aim of the present study is a comparative study of the Thuluth, Nastaliq, and Kufic scripts used in the main porches of mosques in the Safavid and Qajar eras. The research question is: What are the differences and changes in the Thuluth, Nastaliq, and Kufic scripts used in the inscriptions of the main porches of mosques in the Qajar era compared to the period? The method is of an interpretative-historical type with a historical-comparative approach, which is first collected through library study, documents, and information about the scripts and architecture of mosques in the mentioned period. Then the research data is interpreted and analyzed through a field study and the preparation of photographs of these scripts. In addition, the sampling method in this study is a cluster. The findings of the research show that in the main porch of mosques during the Safavid period, Thuluth scripts were used more by artists than Nastaliq and Kufic in inscriptions, but in the Qajar era, Nastaliq and Kufic scripts were popular. The results of the research show that the form, content, and use of Thuluth, Nastaliq, and Kufic inscriptions in the main porch of mosques during the Qajar period are different from those in Safavid architecture, which can be said to be influenced by political and cultural developments.
