Fourth Iranian Empire: Sassanian Empire (224 – 651 CE)

The end of the Parthian Empire came in 224 CE, when the empire was loosely organized and the last king was defeated by Ardashir I, one of the empire's vassals. Ardashir I then went on to create the Sassanian Empire. Soon he started reforming the country both economically and militarily.


The Sassanids established an empire roughly within the frontiers achieved by the Achaemenids, with their capital at Ctesiphon, and called their empire Erânshahr (or Iranshahr, "Dominion of the Aryans", i.e. of Iranians).

During their reign, Sassanid battles with the Roman Empire caused such pessimism in Rome that the historian Cassius Dio wrote:

"Here was a source of great fear to us. So formidable does the Sassanian king seem to our eastern legions, that some are liable to go over to him, and others are unwilling to fight at all."
The Romans suffered repeated losses particularly by Ardashir I, Shapur I, and Shapur II.

Under the Sassanids, Persia expanded relations with China, the arts, music, and architecture greatly flourished, and centers such as the School of Nisibis and Academy of Gundishapur became world renowned centers of science and scholarsahip.

After roughly six hundred years of confrontation and rivalry with the Roman Empire however, a war-exhausted Persia was defeated in the Battle of al-Qâdisiyah in 632 CE in Hilla by invaders from the Arab peninsula.


From the fall of the Sassanian Dynasty to the Mongol invasion

After the Islamic conquest of Persia, Persia was annexed into the Arab Umayyad Caliphate. But the Islamization of Iran was to yield deep transformations within the cultural, scientific, and political structure of Iran's society: The blossoming of Persian literature, philosophy, medicine and art became major elements of the newly-forming Muslim civilization.

Inheriting a heritage of thousands of years of civilization, and being at the "crossroads of the major cultural highways", contributed to Persia emerging as what culminated into the "Islamic Golden Age".

Although influenced, Arabization never succeeded in Iran though, and movements such as the Shuubiyah became catalysts for Persians to regain their independence in their relations with the Arab invaders. It was a Persian, Abu Moslem, who expelled the Umayyads from Damascus and helped the Abbasid caliphs to conquer Baghdad. They frequently chose their "wazirs" (viziers) among Persians, and Persian governors acquired a certain amount of local autonomy. In 822 AD, the governor of Khorasan, Tahir, proclaimed his independence and founded a new Persian dynasty of Tahirids. Others followed in a somewhat tortuous pattern, but Persia was once again able to regain its independence.

The cultural revival of the post-Abbasid period led to a resurfacing of Persian national identity. The resulting cultural movement reached its peak during the ninth and tenth centuries. The most notable effect of the movement was the continuation of the Persian language, the language of the Persians and the official language of Iran to the present day. Ferdowsi, Iran's greatest epic poet, is regarded today as the most important figure in maintaining the Persian language.

During this period, hundreds of scholars and scientists vastly contributed to technology, science and medicine, later influencing the rise of European science during the Renaissance.

The movement continued well into the eleventh century, when Mahmud-a Ghaznavi founded a vast empire, with its capital at Isfahan and Ghazna. Their successors, the Seljuqs, asserted their domination from the Mediterranean Sea to Central Asia. These sovereigns usually named Persians as viziers and Persia became a hotbed of intense cultural activity.


The Mongol Invasion


At the beginning of the thirteenth century Genghis Khan united scattered tribes of Mongolia and started attacking the neighbouring countries. In 1218, he came down from the Altai mountains, marched through Iranian territories in Transoxiana to Khorasan, occupied mainland-Persia, then turned east through India and China. Most of the countries he conquered never really recovered from the bloodshed and destruction he wrought upon them. During this period more than half of Persias population were killed and didn´t reach pre-invasion levels until the 20th century. Holaku, one of the conqueror's grandsons, was left behind to reign over Persia. He very soon became "Persianized". Settled in Maragheh (South of Tabriz), he called Persian men of letters to his court and encouraged the sciences and arts.

But yet another conqueror, Tamerlane (Teymur-e Lang), was to be seduced by the mirage of an Empire of the Orient. In 1370, he entered into Iran. Over a period of thirty years, he conquered Iraq, Syria, Anatolia, Russia and northern parts of India; he was about to invade China when he died in 1404. He chose Samarkand as his capital and his kingdom, while administered by Turkmen, was of distinctively Persian culture.