Introducing the texts on Iranian architecture from different periodsThe period of the ancient Persian Empire
The writing left on the architecture during the period of the ancient Persian Empire is the ancient Persian cuneiform. Prior to this, earlier forms were akkadian cuneiform, and texts including the Cyrus Column, discovered in 1879 at the site of Babylon in Iraq, can be classified as Iranian territory. The main content of the column is the emphasis on freedom of religion and belief, which is generally considered to be the world's first declaration of human rights, and it already embodies the two most basic elements of the writing on the architecture of Iranian cities: clerical power and royal power. The inscriptions on the buildings that have survived for a long time reflect the ideas and ideologies of the time: religion and kingship (monarchy).
A copy of the Cyrus Column, now on display at the British Museum, and at the Museum of World Languages in Shanghai.
It is generally believed that the ancient Persian Empire used two scripts:
One is cuneiform script written in Old Persian;The other is the Aramaic script, which is written in Aramaic for administrative purposes, usually written on papyrus, and only a small amount of literature has survived to this day. The buildings we can see today are mainly the remains of royal palaces, which were an important part of the ancient city. The Old Persian inscriptions, on the other hand, are mainly located on the cliff heights of the road leading to the province of Kermanshah, and are not intended for people but for the gods.
Rest in the Sassanid period
By the time of the Sabbath Sassanid period, no corresponding writing had been found in the royal palace. This is because the palaces of the ancient Persian Empire were built of megaliths and survived for a long timeOn the other hand, the Sabbath and Sassanid emperors built new palaces, mainly masonry structures, which were left after the war. However, there was writing in the Sabbath and Sassanid periods, and it is also preserved on the stone walls of the emperor's tombs, that is, the Middle Persian-Pahlavi language. We can only find a small number of words in the Pahlavi language of that time on the rock face.
Later Pahlavi texts were found mainly from the Islamic period of the 9th century. In order to preserve their faith, the Zoroastrian priests recompiled the Avesta scriptures, which they compiled from memory and explained them in Middle Persian.
Pahlavi. 
Islamic period
By the time of the Islamic period, after the Arab conquest of Iran, Iran accepted Islam and began to have writing on its buildings. At that time, there were Umayyad and Abbasid rule. The Umayyad caliphate required the Arabic language to be used in all ** institutions, but the folk Iranians still spoke Persian, and at the same time Persian gradually began to adopt the Arabic alphabet. It is worth mentioning that the writing system of the Iranians from ancient times to the present day is foreign, but the grammar and most of the vocabulary of the language itself are their own.
Before talking about the writing on the architecture of cities during the Islamic period, we will introduce several scripts in Arabic or later Persian. One is Kufi: Kufi is named after the famous Iraqi city of Kufa, which is either horizontal or vertical, with no dots on the letters, and is mainly used on stone inscriptions. Later, during the Abbasid period, the writing of the Arabic alphabet rapidly developed into six scripts, one of which was a trinity, that is, the writing of the letters was divided into three parts, the lower part accounted for one-third, and the upper vertical line was elongated for two-thirds. The Trinity is mainly embodied in the mosque, as a text not only plays a decorative role in architecture, but also can be used for religious propaganda, through the artistic propaganda of religious and political nature.
For example, in the ancient Iranian city of Isfahan, at one end of its 500-year-old square is the Imam Mosque, the largest mosque at that time. The outline of the gate is all decorated with the Qur'an**, using a trinity;The interior of the mosque is also covered with the Qur'an**, both in Trinity and in Kufi.
Kufi script. 
Trinity. 
Imam Mosque
From the beginning of the 9th century until the present day, the Arabic alphabet is used in the Persian language. This was due to the fact that the small vassal states of the eastern Abbasid Empire began to flourish, and in order to declare their national identity in the former Iranian territory, they began to write Persian in the Arabic alphabet, and by the 15th century, the Nastaligh script appeared. They consider it to be the most beautiful script in Persian and call it "the bride of Islamic calligraphy". Later, this font has continued to this day, and its scope of use is similar to that of Chinese characters. Later, it changed from Nastarig to print, which became more intuitive and can be seen everywhere in Iran.
Nastalig body.
Typographic. Contemporary Iran
Printing is quite commonly used in contemporary Iranian life, but plaques such as Iran's *** Iranian elite schools will be written in Nastalig script to reflect the long history and importance of the unit. In addition to the nastarrig, there are other artistic variants, and religious flags with calligraphy are raised on religious festivals.
On the whole, the inscriptions on the ancient and modern buildings of Iran reflect the strengthening of royal power and clerical power, and at the same time slowly reflect a certain secularization tendency. With the continuous development of cities and societies and the continuous integration of foreign cultures, the Iranian script has also changed, and through its artistic expression, political and religious ideas have subtly influenced and educated its citizens.