Islamization of Iran in the context of "Iranian Intermezzo"

Iran, officially the Islamic Republic of Iran and also known as Persia, is a country in West Asia. It borders Iraq to the west, Turkey, Azerbaijan, and Armenia to the northwest, the Caspian Sea to the north, Turkmenistan to the northeast, Afghanistan to the east, Pakistan to the southeast, and the Gulf of Oman and the Persian Gulf to the south. With a population of over 90 million, Iran ranks 17th globally in both geographic size and population and is the sixth-largest country in Asia. Iran is divided into five regions with 31 provinces. Tehran is the nation's capital, largest city, and financial center.

Home to one of the world's oldest continuous major civilizations, most of Iran was first united as a nation by the Medes under Cyaxares in the 7th century BC and reached its territorial height in the 6th century BC, when Cyrus the Great founded the Achaemenid Empire. Alexander the Great conquered the empire in the 4th century BC. An Iranian rebellion in the 3rd century BC established the Parthian Empire, which later liberated the country. In the 3rd century CE, the Parthians were succeeded by the Sasanian Empire, who oversaw a golden age in the history of Iranian civilization. During this period, ancient Iran saw some of the earliest developments of writing, agriculture, urbanization, religion, and administration. Once a center for Zoroastrianism, the 7th century CE Muslim conquest brought about the Islamization of Iran. Innovations in literature, philosophy, mathematics, medicine, astronomy and art were renewed during the Islamic Golden Age and Iranian Intermezzo, a period during which Iranian Muslim dynasties ended Arab rule and revived the Persian language. This era was followed by Seljuk and Khwarazmian rule, Mongol conquests and the Timurid Renaissance from the 11th to 14th centuries.

The persecution of Zoroastrians is a significant aspect of the later part of the community's history. It is speculated that religious strife existed between Zoroastrians and early Christians, particularly within the context of the Roman–Persian Wars, though the extent of this phenomenon remains unclear. While it was a widespread religion in West Asia for over a millennium, Zoroastrianism began to decline drastically in the aftermath of the Muslim conquest of Persia. The annexation of the Sasanian Empire by the Rashidun Caliphate marked a monumental shift for the former's Zoroastrian-majority society, which was eventually subsumed by the ensuing process of Islamization. During this period, discrimination and harassment against Zoroastrians typically took place in the form of forced conversions and sparse violence. Early Muslims who arrived in the region are recorded to have destroyed Zoroastrian temples or repurposed them as mosques. Zoroastrian practices gradually became circumscribed under Islamic law, which included the levying of the jizya, a tax on non-Muslims.

Early Muslim behaviour with Zoroastrians may have been motivated in part by the fact that they are not explicitly classified as "People of the Book" in the Quran. Although some interpretations do extend this status to the community, the wider consensus among Muslim scholars is that "People of the Book" only identifies the followers of pre-Islamic Abrahamic religions—chiefly Judaism and Christianity—and consequently excludes Zoroastrianism, which is classified as an Iranian religion. Thus, the relative lack of amnesty and privileges for Zoroastrians at this time prompted a large part of the community to flee from Persia to neighbouring India, where they were granted asylum by local kings. The descendants of these Zoroastrian refugees of the early Muslim conquests are known as the Parsi people, who comprise the most prominent community of Indian Zoroastrians today.

Zoroastrianism is considered to be the oldest religion still practiced in Iran. It is an Iranian religion that emerged around the 2nd millennium BCE, spread through the Iranian plateau, and eventually gained official status under the Achaemenid Empire in the 6th century BCE. It remained the Iranian state religion until the 7th century CE, when the Arab conquest of Persia resulted in the fall of the Sasanian Empire to the nascent Rashidun Caliphate. Over time, Zoroastrians became a religious minority amidst the Islamization of Iran, as due to persecution many fled east to take refuge in India. Some of Zoroastrianism's holiest sites are located in Iran, such as Yazd.

Today, Iran has the second largest Zoroastrian population in the world, behind only India and possibly the Kurdistan Region. The official Iranian census of 2011 recorded a total of 25,271 Zoroastrians in the country, but several unofficial accounts suggest higher figures.

Iran, officially the Islamic Republic of Iran and also known as Persia, is a country in West Asia. It borders Iraq to the west, Turkey, Azerbaijan, and Armenia to the northwest, the Caspian Sea to the north, Turkmenistan to the northeast, Afghanistan to the east, Pakistan to the southeast, and the Gulf of Oman and the Persian Gulf to the south. With a population of over 90 million, Iran ranks 17th globally in both geographic size and population and is the sixth-largest country in Asia. Iran is divided into five regions with 31 provinces. Tehran is the nation's capital, largest city, and financial center.

Home to one of the world's oldest continuous major civilizations, most of Iran was first united as a nation by the Medes under Cyaxares in the 7th century BC and reached its territorial height in the 6th century BC, when Cyrus the Great founded the Achaemenid Empire. Alexander the Great conquered the empire in the 4th century BC. An Iranian rebellion in the 3rd century BC established the Parthian Empire, which later liberated the country. In the 3rd century CE, the Parthians were succeeded by the Sasanian Empire, which oversaw a golden age in the history of Iranian civilization. During this period, ancient Iran saw some of the earliest developments of writing, agriculture, urbanization, religion, and administration. Once a center for Zoroastrianism, the 7th century CE Muslim conquest brought about the Islamization of Iran. Innovations in literature, philosophy, mathematics, medicine, astronomy and art were renewed during the Islamic Golden Age and Iranian Intermezzo, a period during which Iranian Muslim dynasties ended Arab rule and revived the Persian language. This era was followed by Seljuk and Khwarazmian rule, Mongol conquests and the Timurid Renaissance from the 11th to 14th centuries.

The Battle of al-Qadisiyyah (Arabic: مَعْرَكَة ٱلْقَادِسِيَّة Maʿrakat al-Qādisīyah; Persian: نبرد قادسیه Nâbārd-e Qâdisiyeh) took place between the armies of the Rashidun Caliphate and the Sasanian Empire in November 636. It resulted in a decisive victory for the Rashidun army and is considered to be one of the most significant engagements of the Muslim conquest of Persia, and thereby of the early Muslim conquests as a whole. After losing al-Qadisiyyah, the Sasanian army was left unable to defend against the Rashidun siege of Ctesiphon, thus being forced to retreat from all of Mesopotamia. This development enabled further Rashidun offensives into the Persian mainland and culminated in the Sasanian Empire's annexation by 651.

It is widely believed that the Rashidun army's advance on al-Qadisiyyah began on 16 November 636 and continued for the next three days. During the battle, Sasanian troops were thrown into disarray following the death of their general Rostam Farrokhzad under uncertain circumstances. The ensuing collapse of their positions marked a cataclysmic defeat that led to the Rashidun army's seizure of Ctesiphon, which had served as the Persian capital city since the Parthian period.