Following the repeated attacks of Ottoman to Tabriz and insecurity in capital, The Safavid King decided to move the capital to Qazvin which they had spent the recreation times in its countryside before. So the capital finally moved to Qazvin by command of shah Tahmasb, the second king of Safavid, in 1544 A.D, and became the second Capital of Safavid dynasty.
After deciding to move the capital from Tabriz to Qazvin, Shah Tahmasb bought some lands known as Zangi Abad and commended to construct a magnificent royal court there.
In its glory times, the royal court had 23 collections of palaces and gardens that were surrounded by 7 gates.
Years later, after fall of Safavid, a commander of Qazvin started to abandon different parts of the royal court to the offices and private sector, so it caused loss of many important monuments including most of palaces and gates.
Now the relict square is generally 8.5 hectares and is located in central part of the city.
Chehel Sotoun palace and Ali Qapu entrance are the most important remained monuments inside it.
Beside them, some monuments from Qajarid or Pahlavid are also noticeable. For example the oldest hotel with European architecture style in Iran, Grand Hotel, the mausoleum of four Jewish Prophets and Omid school, the first modern school in Qazvin, are the samples of relict heritages.