The Safavid dynasty ( 1500-1736), founded by Shah Ismail (1499-1524), restored internal order in Iran and established the Shiite sect as the state religion. After fighting his way to the throne, Shah)smail marched off eastward to attack the Uzbeks, who annually raided the rich province of Khorassan. He was entirely successful in his expedition. But Shah Ismail was unfortunate in having Sultan Salim the Grim, one of the greatest warriors of the house of Os'man, as his enemy. Determined to extirpate the Shiite monarchy before it took root, Salim led the most formidable army of the time against the horsemen of Shah Ismail.
As the result of their victory, the Turks annexed the western provinces of Iran and held them for many years. Shah Ismail died in 1502 AD.
His son, Shah Tahmasp, reigned for over fifty years ( 1524-1575) -a period notable chiefly for protracted and ding-dong struggles with the Turks, which resulted in the loss of Mesopotamia; the removal of the capital from the exposed Tabriz to more secure Qazvin; and the courting of the Iranian monarchy by Western monarchs, hoping to exploit Ottoman-Iranian rivalry and Shiite-Sunnite discord to the disadvantage of the Safavid court and the exotic and Oriental aspect of a largely unknown country. For the first time since the Achaemenians, an Iranian dynasty won international fame.
The Safavid dynasty reached its height during the reign (1587-1629) of Shah Abbas I (Abbas the Great). He defeated not only the Uzbeks, but also the Turks and thereby regained the western provinces of Iran. He drove out the Portuguese, who had established colonies on the Persian Gulf early in the 16th century. But his success in war, great as this was, was surpassed by his achievements in the arts of peace. He removed the seat of government from Qazvin to Esfahan; established trade relations with Great Britain and reorganized the army. Moreover, he restored safety to the caravan routes, built bridges and caravansaries which today, although in decay, testify to the encouragement he gave to merchants and travelers. Superb bridges and stately avenues in Esfahan led to the magnificent Royal Square (now Imam Square), surrounded by great buildings, chief of which was the Royal Mosque (now the Imam Mosque).
 

Europeans of various nationalities visited and described the glories of Iran. Among them were the Shirley brothers, as well as Chardin whose works reveal a deep knowledge of Iran, its history, art, and architecture. Unhappily, for all Abbas the Great's outstanding qualities the Iranian Renaissance was of short duration. The Safavid dynasty struggled on for a hundred years after his death, sustained more by the glories of its past than by any merit in his successors. Shah Safi ( 1628-4 I), Abbas II (1641-68), Suleiman (1668-94) and Hossein (1694-1729) represented a sad degeneration from the saintly race from which they sprang.
The marvel is not that the Safavid dynasty collapsed when it did, but that it took so long to do it. Unrest spread rapidly after about 1715, fostered by the Afghans and the Uzbeks in the northeast, the Kurds in the west and the Arabs in the south. In 1722 a small but highly trained force of Afghans appeared before Esfahan, routed a large Iranian army, captured and looted the city and massacred many of the inhabitants. The Russians and Turks stepped in to seize what they could of the spoils in the north and west; Hossein was captured and abdicated, and his son Tahmasp became Shah in exile and established himself in Mazandaran, where members of the Qajar and Afshar tribes rallied to his banner. It was one of the latter, Nader Quli, who took command of the armies, defeated the Afghans, and in 1730 largely cleared the country.