Abstract
The architecture of the Qajar period due to being in the transition from traditionalism to modernity has special features and this issue makes it important and attractive to study, also the evolution of buildings in this period due to changes in architectural culture and urban life is very important. The influences of various other factors such as climate, cultural relations, the influence of Western architecture, etc., and has had a remarkable effect on the formation of the architecture of Tehran’s palaces. In this study, in addition to studying the above factors in the field of differences, especially in how the architectural effects of each era, its evolution in each period is also examined. In this regard, the present study examines the architecture of palaces of each period of the Qajar kings and examines the process of its changes and compares their differences and similarities in terms of architectural style. In this study, in order to understand why and how. The achievement of architects in this specific pattern and the degree of influence of past techniques and the impact of Western architecture on the architecture of this period are presented. The most important buildings of this period have been studied by field observation and library studies and previous researches by descriptive-analytical and comparative research methods, and the differences and commonalities of each of them have been evaluated. Considering that no significant research has been done on Tehran palaces and Qajar period architecture from the point of view of stylistics and their characteristics, this article can cover the existing research gap to some extent by recognizing the factors and the formation of palaces architecture. The findings of this study show that despite some influences of Western architecture in this period, the architecture of this period is still based on the basic principles of Iranian-Islamic architecture such as the principle of introversion, privacy and... 
Keywords: Qajar Period, Tehran Palaces, Golestan Palace, Aristocratic Mansions.

Introduction
The formation of architecture of the Qajar period can be divided into two time stages. Safavid period architecture and Isfahan style and the second part are integrated and taken from the architectural style of the second half of the 18th and 19th centuries. Maghrib is the earth, this style entered the architecture of Iran as a symbol of modernity and strongly influenced the architecture of Iran (Rezaei Nabi and Salehi Tabrizi, 2012: 6). Of course, this effect is much greater in the last years of the Qajar period than in the early years. In fact, the reign of the last Qajar king can be considered completely different from previous periods. Some historians consider this period as a mere imitation of Western architectural style (Talebzadeh, 2007: 14). Others, however, believe that the self-critical view resulting from the defeat in the Iran-Russia wars caused transformational tendencies to form in Iranian society during the Qajar period, and that the different Qajar architecture is the product of this idealistic approach. This can be attributed to the lack of importance to the tradition and original identity of the past in this period, and socially, the class gap between sections of society has increased and also political relations with Western countries caused the affluent strata of society after traveling to Western countries with what. They chose Western architecture and used it in their mansions (Saremi and Radmard, 1997: 143) and because the information was transmitted through the minds of these people, it was similar to the same building - with local and experimental materials and technology. And not scientific - they built, which often formed a fusion of traditional and Western architecture.
Objectives and necessity of research: Our purpose in this article is to examine the historical maps and documents and the results of field research, the formation and changes over time on the palaces of this period. In this research, the process of formation and evolution of Qajar period architecture and the influence of Western architecture on it are studied. The necessity of such research can be expressed in the physical analysis and typology of palaces of this period.
Research Questions and Hypotheses: Considering the fact that the establishment of the Tehran Government Citadel coincides with the capitalization of this city and the construction of the Nasserite fence, the main question is how the palaces of the Qajar period were formed and evolved? The present study seeks to understand why and how architects achieve this specific pattern and be influenced by past techniques and Western neoclassical style, as well as how they relate to each other and their similarities.
Research Methodology: The research method is based on the purpose of basic research, the research method is descriptive-analytical and comparative, the subject matter is obtained using the basic and basic data required through field studies. In order to compare and contrast the simultaneous data, the method of data collection has been done in a library manner and by comparing and analyzing them, it has come to a conclusion.

Background Research
In terms of the background and thematic background of the research, it should be acknowledged that fortunately in the field of architecture of the Qajar period and especially Golestan Palace, extensive research and studies have been conducted by several researchers, the most important of which are in the form of two thematic axes. They include general architectural studies of the Qajar period as well as studies on the architecture of Qajar royal mansions, some of which are mentioned below. One of these researches can be found in the book History of Construction.

Conclusion
In the traditional architecture of Iran, one point has always been considered by architects and that is the observance of interior and exterior spaces in architecture. From ancient times, Iranians were more spiritually and emotionally compatible than indoor and outdoor spaces to modern spaces. These elements and patterns were observed and preserved in Iranian architecture during the Safavid, Zandi and the first years of Qajar rule.
Certainly, architecture changes in each period in accordance with the lifestyle of human beings in each country. From the middle of the Qajar period, with the change of intellectual resources and ideas governing the society and also being aware of the developments, different needs were felt than in the past. These needs did not develop much at first and were more prominent among the courtiers and the affluent classes. They considered responding to these needs and the solution in modeling Western methods. The establishment of the Academy of Arts, sending students to Europe, hiring foreign teachers and publishing newspapers changed the social and political attitude in the Qajar period. The atmosphere of Qajar architecture followed the same attitude. From the middle of the Nasserite era onwards, the confrontation between tradition and modernity led to the victory of modernity, and architecture has since lost its ancient forms and taken on a Western appearance. The palaces of this period played the most important role in carrying out this evolution by being a pioneer in reflecting the architectural developments of their time. This architecture is a break from the previous tradition and in line with Western traditions and the achievements of Western civilization. The weakness of the Qajar government and the inability of the traditional system to confront the Western traditions created changes and currents in Iranian architecture. Iran’s entry into the Third World during the Qajar period caused Western civilization to become a model in many fields, including architecture, and among these, the first examples were seen in palaces and mansions. The decline of Iranian architectural traditions began in the middle of the Qajar period. In fact, the Qajar period is the era of weakening the historical and original Iranian traditions and the development and spread of Western architecture in Iran.
 Over time, in the years following the reign of Fath Ali Shah, buildings were erected that were considered the source of changes in traditional architecture. With the construction of a building such as Shams al-Amara, which has not benefited much from Western technology and can only be pointed out to be high-rise. Towards the end of Nasser al-Din Shah’s reign, the shape and construction of buildings and palaces shifted to the European neoclassical style.
As we approach the end of the Qajar rule, the construction of buildings has become easier and there is no more traditional and introverted architecture, and modern buildings are being replaced by western and extroverted methods. Towards the end of this period, a number of elements of European architecture entered Iranian architecture and were used in combination with the same so-called traditional architecture. Some of these elements were borrowed from classical and neoclassical European architecture, and others were influenced by modern architecture. In short, Qajar architecture rightly upgraded the old Iranian architecture along with Western architecture, principles, principles and patterns and created innovations in terms of space. But it did not seem to have the strength to create a new architecture. In fact, in this period, due to the influence of Western architecture in Iran, our architects immersed it in the principles and patterns of traditional Iranian architecture, but by combining the two, they could not create a new style or pattern.