But Tehran was still not the Persian capital at that point; under Tahmasb I’s reign, Qazvin was made capital, moving from the city of Tabriz which was too close for comfort to the border with the Ottoman Empire. (To learn more about the Safavid Dynasty, click here.) Tahmasb’s successors added more buildings to Tehran, turning it into an important trade centre. In the early 18th century, Karim Khan of the Zand dynasty ordered a palace and a government office to be built there but later chose Shiraz as the capital.