After the death of Malik Shah in 1092, Iran once again reverted to petty dynasties. During this time, Genghis (Chinggis) Khan brought together a number of Mongol tribes and led them on a devastating sweep through China. Then, in 1219, he turned his 700,000 forces west and quickly devastated Bukhara, Samarkand, Balkh, Merv, and Neyshabur. Before his death in 1227, he had reached western Azarbaijan, pillaging and burning cities along the way.

The Mongol invasion was disastrous to the Iranians. Destruction of qanat irrigation systems destroyed the pattern of relatively continuous settlement, producing numerous isolated oasis cities in a land where they had previously been rare (see Water , ch. 3). A large number of people, particularly males, were killed between 1220 and 1258, the population of Iran dropped drastically.

Mongol rulers who followed Genghis Khan did little to improve Iran's situation. Genghis's grandson, Hulagu Khan, turned to foreign conquest, seizing Baghdad in 1258 and killing the last Abbasid caliph. He was stopped by the Mamluk forces of Egypt at Ain Jalut in Palestine. Afterward he returned to Iran and spent the rest of his life in Azarbaijan.

A later Mongol ruler, Ghazan Khan (1295-1304), and his famous Iranian vizier, Rashid ad Din, brought Iran a partial and brief economic revival. The Mongols lowered taxes for artisans, encouraged agriculture, rebuilt and extended irrigation works, and improved the safety of the trade routes. As a result, commerce increased dramatically. Items from India, China, and Iran passed easily across the Asian steppes, and these contacts culturally enriched Iran. For example, Iranians developed a new style of painting based on a unique fusion of solid, two-dimensional Mesopotamian painting with the feathery, light brush strokes and other motifs characteristic of China. After Ghazan's nephew, Abu Said, died in 1335, however, Iran again lapsed into petty dynasties--the Salghurid, Muzaffarid, Inju, and Jalayirid--under Mongol commanders, old Seljuk retainers, and regional chiefs.

Tamerlane, variously described as of Mongol or Turkic origin, was the next ruler to achieve emperor status. He conquered Transoxiana proper and by 1381 established himself as sovereign. He did not have the huge forces of earlier Mongol leaders, so his conquests were slower and less savage than those of Genghis Khan or Hulagu Khan. Nevertheless, Shiraz and Esfahan were virtually leveled. Tamerlane's regime was characterized by its inclusion of Iranians in administrative roles and its promotion of architecture and poetry. His empire disintegrated rapidly after his death in 1405, however, and Mongol tribes, Uzbeks, and Bayundur Turkomans ruled roughly the area of present-day Iran until the rise of the Safavid dynasty, the first native Iranian dynasty in almost 1,000 years.

Data as of December 1987