The capital of a country is the most important city of this country from a political and administrative point of view, as well as very often from an economic point of view.

The capital of a country is the most important city of this country from a political and administrative point of view, as well as very often from an economic point of view. In other words, "it represents the authority, the legitimacy and the sovereignty" of a country. The city of Tehran, capital of Iran is, with its 8,429,807 inhabitants and its 686 km2 of surface, the largest commercial center of the country and one of the most important capitals of the biggest continent of the world, Asia. Since it is the capital, Tehran is the strategic and political heart of the country, and in recent decades, its historical and cultural dimension is also becoming increasingly important.

Geographically, Tehran is located on the southern foothills of central Alborz. Its climate is dry and hot in summer, cold in the north and temperate in the south in winter. In recent decades, air pollution has made life difficult for its inhabitants, and many believe that the surrounding mountains are blocking the winds that could help reduce pollution. The word Tehran, according to a popular etymology, is composed of the combination of two words: "Teh" which means "under" and "ran" which is defined by hill. "Tehran" therefore, refers, according to this etymology, to an inhabited underground place. This indeed suggests the life of the first inhabitants of this place. Because the first Tehranise, fleeing the war, built their houses a few meters below the surface. It was an effective way to "repel enemies". Some archaeological studies and "topographic and climatic reports" have also shown that these early inhabitants lived between the Tochal mountain north of Tehran and Cheshmeh Ali, and near the ancient Rey in prehistoric times. Another discovery shows that human groups lived in Cheshmeh Ali and Gheytarieh eight thousand years ago. Nevertheless, traces of the presence of these very old Tehran were mostly destroyed during the rapid urbanization of the city in the second half of the twentieth century.

At the same time, for some scholars like Ahmad Kasravi, an Iranian historian and linguist, the term "Tehran" is the product of a derivation of the term shot-at. This last word means "plain, plain desert", or a warm place which is located near a cold place or shemran: Tehran, therefore evokes a Tahran, "hot place", as opposed to Shemran, "cold place". Whatever the correct etymology of Tehran, it is confirmed that it began to be inhabited by Aryan tribes at the end of the second millennium BC. A first group settled next to a Permanent river, named Cheshmeh Ali in the Islamic era. According to specialists, at the root of the prosperity and geographical development of Tehran, there is "the geographical location of the mountains and the desert, the abundance of sources of water and arable land ". In the fourteenth century, according to Clavijo, ambassador of the King of Spain, the common language of the inhabitants of Tehran was the Persian language, and the inhabitants lived in dwellings built by human hands. It is especially from the Qadjair era that Tehran, become capital, becomes important against Rey, her eminent neighbor, which she eventually swallows.


Tehran as capital

After the invasion of the Mughals in the 13th century and the near-total destruction of Rey, one of Iran's major cities from the 10th to the 18th century, Tehran began to transform itself. Originally a small village, it gradually became a prosperous town.

It is from the Safavid era that we can trace the development of Tehran. It is the Safavid Shah TahmaspI who gives importance to this village by choosing it as the headquarters of the army. In this way, Tehran changes its face and is gradually transformed into a military and political city. Then, the construction of a large mosque and facilities for civilians attracts new inhabitants and the social aspect of the country also changes to become more and more popular and urban. Three dynasties later, Agha Mohammad Khan Qajar takes the power and founds the Qajar dynasty in 1794, after having eliminated the last representative of the Zand dynasty, Lotf Ali Khan Zand. A year later, in 1795, he chose Tehran as the new capital of the kingdom. As Tehran is at the crossroads of the east-west national road that stretches at the foot of the Alborz mountains and the paths that lead to the "oases of central Iran and the basins of Fars". It has a strategic value, especially at a time when Russia is threatening the country.

Tehran gained even more momentum under the reign of Fath Ali Shah Qadjar, but it was during the fifty years of Nassereddin Shah's rule that the city prospered the most, especially thanks to the efforts of the modernist Chancellor Amir Kabir. This chancellor is notably the founder of the Dar-ol-Fonoun academy in 1849. This first modern academy was founded on the model of the Polytechnic School and several disciplines were taught according to the achievements of modern science and pedagogy. It was also in 1849 that Amir Kabir built the first modern Iranian public hospital, called Marizkhaneh.

During the Qajar period, the notion of capital is linked to that of international relations [18]. It is therefore defined as an open door abroad or even better, as the door of the West. Tehran was in 1907 a commercial hub to Russia, Istanbul and Europe
With the seizure of power by Reza Khan and the appearance of the Pahlavi dynasty, Tehran strongly grows following the establishment of a modern national state by Reza Shah. The latter, influenced by the modernity of Western countries, wants not only a modern capital, but also a modern and prosperous country. This is why he is ordering numerous projects including the construction of factories, railway stations and airports at Dooshan Tappeh and Ghaleh Morghi and the University of Tehran. This era is then considered as that of the modernization of Tehran.

In one hundred years, this city has undergone intense changes, the most remarkable of which is perhaps its demographic evolution and "this new demographic dimension only gives more weight to the essential function of this city as bridge of modernity".

According to some sociologists, the Islamic Revolution provoked the desecration of Tehran. Thus, the crisis of this city would have been triggered "by the disappearance of the top of the social pyramid" or by the impossibility to develop on "the vertical axis of the social promotion". The absence of a policy of public facilities, particularly transport, as well as long-term urban planning, would have made Teheran lose "its identity and its dynamic of social promotion".