The Sasanian era is one of the most influential periods in Iran's history. It also marks the third rise of a great Iranian empire, a dynasty that rivaled its predecessor, the Achaemenids, who too, like the Sassanids, were native to the province of Pars, and in some instances the Parthians, in glory and power. Although it fought many campaigns against the Romans/Byzantines in the west and the nomadic people in the east and north, the Sasanian Empire met its demise not by the Byzantine-Roman Empire, but by emerging Arab Muslims from across its southern borders. However, the conflict with the Byzantines greatly contributed to its weakness, by draining Sassanid resources, leaving it a prime target for the Muslims.
Sassanid society was divided into four classes: priests, warriors, secretaries, and commoners. The latter formed the bulk of the population, served as its sole tax base, and remained its poorest class.
At the climax of Khosrau II's ambitious Byzantine territory conquests in the Levant and much of Asia Minor, taxes rose dramatically, and most people could not pay. Years of Sassanid-Byzantine wars had ruined trade routes and industry, the population's main income sources. The existing Sassanid administrative structure proved inadequate when faced with the combined demands of a suddenly expanded empire, economy, and population. Rapid turnover of rulers and increasing provincial landholder (dehqan) power further diminished the Sassanids. Over a period of fourteen years and twelve successive kings, the Sassanid Empire weakened considerably, and the power of the central authority passed into the hands of its generals. Even when a strong king emerged following a series of coups, the Sassanids never completely recovered.
Years of warfare between the Sassanids and the Byzantines, as well as the strain of the Khazar invasion of Transcaucasia, had exhausted the army. No effective ruler followed Khosrau II, causing chaos in society and problems in the provincial administration, until Yazdegerd III rose to power. All these factors undermined the strength of the Persian army. Yazdegerd III was merely 8 years old when he came to the throne and, lacking experience, did not try to rebuild the army. The Sassanid Empire was highly decentralized, and was in fact a "confederation" with the Parthians, who themselves retained a high level of independence. However, after the last Sassanid-Byzantine war the Parthians wanted to withdraw from the confederation, and the Sasanians were thus ill-prepared and ill-equipped to mount an effective and cohesive defense against the Muslim armies. Moreover, the powerful northern and eastern Parthian families, the Kust-i Khwarasan and Kust-i Adurbadagan, withdrew to their respective strongholds and made peace with the Arabs, refusing to fight alongside the Sassanids.
Pourshariati argues that the Arab conquest of Mesopotamia "took place, not, as has been conventionally believed, in the years 632–634, after the accession of the last Sasanian king Yazdgerd III (632–651) to power, but in the period from 628 to 632." An important consequence of this change in timeline means that the Arab conquest started precisely when the Sasanians and Parthians were engaged in internecine warfare over who was to succeed the Sassanid throne.
When Arab squadrons made their first raids into Sassanid territory, Yazdegerd III did not consider them a threat, and he refused to send an army to encounter the invaders. When the main Arab army reached the Persian borders, Yazdegerd III procrastinated in dispatching an army against the Arabs. Even Rostam-e Farokhzad, who was both Eran Spahbod and Viceroy, did not see the Arabs as a threat. Without opposition, the Arabs had time to consolidate and fortify their positions.
When hostilities between the Sassanids and the Arabs finally began, the Persian army faced fundamental problems. While their heavy cavalry had proved effective against the Roman forces, it was too slow and regimented to act with full force against the agile and unpredictable lightly armed Arab cavalry and foot archers.
The Persian army had a few initial successes. War elephants temporarily stopped the Arab army, but when Arab veterans returned from the Syrian fronts where they had been fighting against Byzantine armies, they taught the Arab army how to deal with these beasts. Thus war elephants had lost their effectiveness on the battlefield.
These factors contributed to the decisive Sassanid defeat at the Battle of al-Qādisiyyah. The Persians, who had only one generation before conquered Egypt and Asia Minor, lost decisive battles when nimble, lightly armed Arabs accustomed to skirmishes and desert warfare attacked them. The Arab squadrons defeated the Persian army in several more battles culminating in the Battle of Nahāvand, the last major battle of the Sassanids. The Sassanid dynasty came to an end with the death of Yazdegerd III in 651.
The Battle of Badghis was fought in 654 between the Karen family and their Hephthalite allies against the Rashidun Caliphate.Battle of Chains
The Battle of Sallasil (Arabic: معركة ذات السلاسل Dhat al-Salasil) or the Battle of Chains was the first battle fought between the Rashidun Caliphate and the Sassanid Persian Empire. The battle was fought in Kuwait (Kazima) soon after the Ridda Wars were over and Eastern Arabia was united under the authority of Caliph Abu Bakr. It was also the first battle of the Rashidun Caliphate in which the Muslim army sought to extend its frontiers.Battle of Nishapur
The Battle of Nishapur was fought in 652 between the Karen family and the Rashidun Caliphate along with their allies the Kanārangīyān family.Battle of Spahan
The Battle of Spahan was fought between the Rashidun Caliphate and the Sasanian Empire in 642. The Arabs were victorious during the battle, where they reportedly killed the Mihran commander Shahrvaraz Jadhuyih. After the battle, the Arabs made peace with Fadhusfan, the governor of the city. According to Abu No'aym, many people were killed or enslaved after the conquest and the settlement pattern of the region changed. Isfahan capitulated by 644 after a faw failed revolts and treaties for paying taxes and tributes in exchange for military protection were drawn up.Battle of Waj Rudh
The Battle of Waj Rudh was fought in 642/643 between the Rashidun Caliphate under Nu'man, and the Sasanian Empire under the Dailamite Muta, the Parthian Farrukhzad and Isfandiyar, and the Armenian Varaztirots. The battle was fought in Waj Rudh, a village in Hamadan. The Sasanians were defeated under heavy casualties, which included the death of Muta and Varaztirots.Battle of the Bridge
The Battle of the Bridge or the Battle of al-Jisr (Arabic: معركة الجسر) was a battle at the bank of the Euphrates river between Arab Muslims led by Abu Ubaid al-Thaqafi, and the Persian Sasanian forces led by Bahman Jaduya. It is traditionally dated to the year 634, and was the only major Sassanian victory over the invading Muslim armies.Derafsh Kaviani
Derafsh Kaviani (Persian: درفش کاویانی) was the legendary royal standard and vexilloid of Iran (Persia) used since ancient times until the fall of the Sasanian Empire. Following the defeat of the Sassanids at the Arab conquest of Persia, the Sassanid standard was recovered by one Zerar bin Kattab, who received 30,000 dinars for it. After the jewels were removed, Rashidun Caliph Umar is said to have burned the standard. The banner was also sometimes called the "Standard of Jamshid" (Drafš-ī Jamshid درفش جمشید), the "Standard of Fereydun" (Drafš-ī Freydun درفش فریدون) and the "Royal Standard" (Drafš-ī Kayi درفش کیی).House of Ispahbudhan
The House of Ispahbudhan or the House of Aspahbadh was one of the seven Parthian clans of the Sasanian Empire. Like the Sasanians, they claimed descent from the Achaemenids. They also claimed descent from the legendary Kayanid figure Isfandiyar, who was the son of the Vishtaspa, who according to Zoroastrian sources was one of Zoroaster's early followers.House of Sasan
The House of Sasan was the house that founded the Sasanian Empire, ruling this empire from 224 to 651. It began with Ardashir I, who named the dynasty as Sasanian (also known as Sassanid) in honour of his grandfather, Sasan, and after the name of his tribe.
The Shahanshah was the sole regent, head of state and head of government of the empire. At times, power shifted de facto to other officials, namely the spahbed.Hyrcania
Hyrcania () (Greek: Ὑρκανία Hyrkania, Old Persian: 𐎺𐎼𐎣𐎠𐎴 Varkâna, Middle Persian: 𐭢𐭥𐭫𐭢𐭠𐭭 Gurgān, Akkadian: Urqananu) is a historical region composed of the land south-east of the Caspian Sea in modern-day Iran, bound in the south by the Alborz mountain range and the Kopet Dag in the east.The region served as a satrapy (province) of the Median Empire, a sub-province of the Achaemenid Empire, and a province within its successors, the Seleucid, Arsacid and Sasanian empires. Hyrcania bordered Parthia to the east (later known as Abarshahr), Dihistan to the north, Media to the south and Mardia to the west. After the fall of the Sasanian Empire in 651 AD, Hyrcania was known as Tabaristan.Jalinus
Jalinus Fahmi (Galen) (Persian: گلینوش) was an Armenian nobleman during the late Sassanian era. He was the commander of the guard over Khosrau II, during the latter's imprisonment. Jalinus was a Sasanian commander during the Arab Muslim invasion of Mesopotamia.Kavadh II
Shērōē (also spelled Shīrūya, New Persian: شیرویه), better known by his dynastic name of Kavadh II (Middle Persian: 𐭪𐭥𐭠𐭲 Kawād; New Persian: قباد Qobād or Qabād), was king (shah) of the Sasanian Empire briefly in 628. He was the son of Khosrow II (r. 590–628), whom he succeeded after having him overthrown in a coup d'état. Kavadh's reign is seen as a turning point in Sasanian history, and has been argued by some scholars as playing a key role in the fall of the Sasanian Empire.King of Kings
King of Kings (Akkadian: šar šarrāni, Old Persian: Xšâyathiya Xšâyathiyânâm, Middle Persian: šāhān šāh, Greek: Βασιλεὺς Βασιλέων, Basileus Basileion, Georgian: mepet mepe Ge'ez: ንጉሠ ነገሥት, Nəgusä Nägäst) was a ruling title employed primarily by monarchs based in the Middle East. Though most commonly associated with Persia, especially the Achaemenid and Sasanian Empires, the title was originally introduced during the Middle Assyrian Empire by king Tukulti-Ninurta I (reigned 1233–1197 BC) and was subsequently used in a number of different kingdoms and empires, including the aforementioned Persia, various Hellenic kingdoms, Armenia, Georgia and Ethiopia.
The title is commonly seen as equivalent to that of Emperor, both titles outranking that of king in prestige, stemming from the medieval Byzantine Emperors who saw the Shahanshahs of the Sasanian Empire as their equals. The last reigning monarchs to use the title of Shahanshah, those of the Pahlavi dynasty in Iran (1925–1979) also equated the title with "Emperor". The rulers of the Ethiopian Empire used the title of Nəgusä Nägäst (literally "King of Kings"), which was officially translated into "Emperor". The female variant of the title, as used by the Ethiopian Zewditu, was Queen of Kings (Ge'ez: Nəgəstä Nägäst). In the Sasanian Empire, the female variant used was Queen of Queens (Middle Persian: bānbishnān bānbishn).Pushtigban
The pushtigban was an elite military unit of the Sasanian Empire, charged with the protection of the Persian Emperor.
They were stationed during peacetime in the royal capital of Ctesiphon and were drawn from the best of the ranks of the Sassanid Savārān cavalry. They numbered 1000 men, under the command of the pushtigban-salar ; in battle they fought mostly as cataphracts, heavily armed and armoured horseman who would charge enemy positions with tremendous momentum.
A sub-unit of pushtigban were the gyan-avspar, the "sacrificers of their lives" - the best of the pushtigban. The pushtigban fought with distinction and zeal befitting their name during Julian's invasion of Persia in the 4th century AD.
The pushtigban disappeared with the Muslim conquest of Persia, that led to the Fall of the Sasanian Empire.Seven Great Houses of Iran
The Seven Great Houses of Iran, also known as the Seven (Great) Houses, or Seven Parthian clans, were seven feudal aristocracies of Parthian origin, who were allied with the Sasanian court.Shapur-i Shahrvaraz
Shapur-i Shahrvaraz (Middle Persian: 𐭱𐭧𐭯𐭥𐭧𐭥𐭩𐭩 𐭧𐭱𐭨𐭥𐭥𐭥𐭰), also known as Shapur V, was a Sasanian usurper who reigned for a short time in 630 until he was deposed in favor of Azarmidokht.Shapur IV
Shapur IV (Middle Persian: 𐭱𐭧𐭯𐭥𐭧𐭥𐭩 Šāhpuhr), was king of Persian Armenia from 415 to 420, who briefly ruled the Sasanian Empire in 420.Siyavakhsh
Siyavakhsh (also spelled Siyavash) was an Iranian aristocrat from the House of Mihran who was descended from Bahram Chobin, the famous spahbed of the Sasanian Empire and briefly its emperor.Wuzurgan
Wuzurgan (Middle Persian: 𐭥𐭰𐭥𐭫𐭢, meaning "grandees" or the "great ones"), also known by its Modern Persian form of Bozorgan (بزرگان), was the third class-rank of the four or five types of the Sasanian aristocracy. After the fall of the Sasanian Empire, they reappear under the Dabuyid dynasty.