Roman–Persian wars in the context of "History of Iran"

The History of Iran (also known as Persia) is intertwined with Greater Iran, which is a region encompassing all of the areas that have witnessed significant settlement or influence by the Iranian peoples and the Iranian languages – chiefly the Persians and the Persian language. Central to this region is the Iranian plateau, now largely covered by modern Iran. The most pronounced impact of Iranian history can be seen stretching from Anatolia in the west to the Indus Valley in the east, including the Levant, Mesopotamia, the Caucasus, and parts of Central Asia. It also overlaps or mingles with the histories of many other major civilizations, such as India, China, Greece, Rome, and Egypt.

Iran is home to one of the world's oldest continuous major civilizations, with historical and urban settlements dating back to the 5th millennium BC. The Iranian plateau's western regions integrated into the rest of the ancient Near East with the Elamites (in Ilam and Khuzestan), the Kassites (in Kuhdesht), the Gutians (in Luristan), and later with other peoples like the Urartians (in Oshnavieh and Sardasht) near Lake Urmia and the Mannaeans (in Piranshahr, Saqqez and Bukan) in Kurdistan. German philosopher Georg Wilhelm Friedrich Hegel called the Persians the "first Historical People" in his Lectures on the Philosophy of World History. The sustained Iranian empire is understood to have begun with the rise of the Medes during the Iron Age, when Iran was unified as a nation under the Median kingdom in the 7th century BC. By 550 BC, the Medes were sidelined by the conquests of Cyrus the Great, who brought the Persians to power with the establishment of the Achaemenid Empire. Cyrus' ensuing campaigns enabled the Persian realm's expansion across most of West Asia and much of Central Asia, and his successors would eventually conquer parts of Southeast Europe and North Africa to preside over the largest empire the world had yet seen. In the 4th century BC, the Achaemenid Empire was conquered by the Macedonian Empire of Alexander the Great, whose death led to the establishment of the Seleucid Empire over the bulk of former Achaemenid territory. In the following century, Greek rule of the Iranian plateau came to an end with the rise of the Parthian Empire, which also conquered large parts of the Seleucids' Anatolian, Mesopotamian, and Central Asian holdings. While the Parthians were succeeded by the Sasanian Empire in the 2nd century, Iran remained a leading power for the next millennium, although the majority of this period was marked by the Roman–Persian Wars.

The Pax Romana (Latin for 'Roman peace'; IPA: [paːks rɔːˈmaːna]) is a roughly 200-year-long period of ancient Rome that is identified as a golden age of increased and sustained Roman imperialism, prosperous stability, hegemonic power, regional expansion, and relative peace and order, although it still featured a number of internal revolts and external wars, including the Roman–Persian wars. Traditionally, the onset is understood to be the ascent of Augustus, who also founded the Roman principate, in 27 BC. Conversely, the end of the era is considered as 180 AD with the death of Marcus Aurelius, the last of the "Five Good Emperors".

It was during this period that the Roman Empire achieved its greatest territorial extent under Trajan in 117. Additionally, the Roman Empire's population is estimated to have peaked at 70 million people during the Pax Romana, accounting for 33% of the world's population. Following the Pax Romana, and according to Cassius Dio, the dictatorial reign of Commodus, later followed by the Year of the Five Emperors and the Crisis of the Third Century, marked Rome's descent "from a kingdom of gold to one of iron and rust".

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.

The Byzantine–Sasanian War of 602–628, also called the Last Great War of Antiquity, was fought between the Byzantine Empire and the Sasanian Empire. It was the final and most devastating conflict of the Roman–Persian wars (54 BC – AD 628). The previous war between the two powers had ended in 591 after the emperor Maurice helped the Sasanian king Khosrow II regain his throne. In 602, Maurice was murdered by his political rival Phocas. Khosrow declared war, ostensibly to avenge the death of the deposed emperor Maurice. This became a decades-long conflict, the longest war in the series, and was fought throughout the Middle East, the Aegean Sea, and before the walls of Constantinople itself.

From 602 to 622, the Sassanians gradually conquered much of the Levant, parts of Anatolia, and—for the first time—Egypt and several islands in the Aegean Sea. The counter-attacks of the new Byzantine emperor Heraclius from 622 to 626 eventually forced the Persians onto the defensive. Allied with the Avars and Slavs, the Persians attempted to take Constantinople in 626, but were defeated. In 627, allied with Turks, Heraclius invaded the heartland of Persia. After the Battle of Nineveh (627), Iranian forces were finally broken, forcing civil war-torn Persia to seek peace.

The Ghassanids, also known as the Jafnids, were an Arab tribe. Originally from South Arabia, they migrated north to the Levant in the 3rd century and established what would eventually become a Christian kingdom under the aegis of the Byzantine Empire. However, some of the Ghassanids may have already adhered to Christianity before they emigrated from South Arabia to escape religious persecution.

As a Byzantine vassal, the Ghassanids participated in the Byzantine–Sasanian Wars, fighting against the Sasanian-allied Lakhmids, who were also an Arabian tribe, but adhered to the non-Chalcedonian Church of the East. The lands of the Ghassanids also acted as a buffer zone protecting lands that had been annexed by the Romans against raids by Bedouins.

The history of Iran (also known as Persia) is intertwined with Greater Iran, which is a region encompassing all of the areas that have witnessed significant settlement or influence by the Iranian peoples and the Iranian languages – chiefly the Persians and the Persian language. Central to this region is the Iranian plateau, now largely covered by modern Iran. The most pronounced impact of Iranian history can be seen stretching from Anatolia in the west to the Indus Valley in the east, including the Levant, Mesopotamia, the Caucasus, and parts of Central Asia. It also overlaps or mingles with the histories of many other major civilizations, such as India, China, Greece, Rome, and Egypt.

Iran is home to one of the world's oldest continuous major civilizations, with historical and urban settlements dating back to the 5th millennium BC. The Iranian plateau's western regions integrated into the rest of the ancient Near East with the Elamites (in Ilam and Khuzestan), the Kassites (in Kuhdesht), the Gutians (in Luristan), and later with other peoples like the Urartians (in Oshnavieh and Sardasht) near Lake Urmia and the Mannaeans (in Piranshahr, Saqqez and Bukan) in Kurdistan. German philosopher Georg Wilhelm Friedrich Hegel called the Persians the "first Historical People" in his Lectures on the Philosophy of World History. The sustained Iranian empire is understood to have begun with the rise of the Medes during the Iron Age, when Iran was unified as a nation under the Median kingdom in the 7th century BC. By 550 BC, the Medes were sidelined by the conquests of Cyrus the Great, who brought the Persians to power with the establishment of the Achaemenid Empire. Cyrus' ensuing campaigns enabled the Persian realm's expansion across most of West Asia and much of Central Asia, and his successors would eventually conquer parts of Southeast Europe and North Africa to preside over the largest empire the world had yet seen. In the 4th century BC, the Achaemenid Empire was conquered by the Macedonian Empire of Alexander the Great, whose death led to the establishment of the Seleucid Empire over the bulk of former Achaemenid territory. In the following century, Greek rule of the Iranian plateau came to an end with the rise of the Parthian Empire, which also conquered large parts of the Seleucids' Anatolian, Mesopotamian, and Central Asian holdings. While the Parthians were succeeded by the Sasanian Empire in the 2nd century, Iran remained a leading power for the next millennium, although the majority of this period was marked by the Roman–Persian Wars.