The Muslim conquests in present-day Afghanistan, a country at the crossroads of central and west Asia, began during the last phase of Muslim conquest of Persia, as the Arab Muslims expanded eastwards to Khorasan, Sistan and Transoxiana. Fifteen years after the battle of Nahāvand in 642 AD, they controlled all the Sasanian domains except those in Afghanistan. The region was not completely Islamized until the period between 10th and 12th centuries, under Ghaznavid and Ghurid dynasties, who patronized Muslim religious institutions.
Khorasan and Sistan, where Zoroastrianism was well-established, were conquered in the 7th century. The Arabs had begun to move towards the lands east of Persia in the end of 7th century.Historic Cities of the Islamic World, ed. C.E. Bosworth, (Brill, 2007), 153. The Muslim frontier in modern Afghanistan had become stabilized after the first century of the Lunar Hijri calendar as the relative importance of the Afghan areas diminished. From historical evidence, it appears Tokharistan (Bactria) was the only area conquered by Arabs where Buddhism heavily flourished. Balkh's final conquest was undertaken by Qutayba ibn Muslim in 705.
The eastern regions of Afghanistan were at times considered politically as parts of India. Buddhism and Hinduism held sway over the region until the Muslim conquest. Kabul and Zabulistan which housed Buddhism and other Indian religions, offered stiff resistance to the early Muslim advance. Nevertheless, the Arab Umayyads regularly claimed nominal overlordship over the Zunbils and Kabul Shahis.
The expeditions of caliph al-Ma'mun (r. 813–833 AD) were the last by the Arabs in Kabul and Zabul. The king of Kabul was captured by him and converted to Islam. The last Zunbil was killed by Ya'qub ibn al-Layth, the founder of the Saffarid dynasty, along with his former overlord Salih ibn al-Nadr in 865. Meanwhile, the Hindu Shahis of Kabul were defeated by Mahmud of Ghazni. Indian soldiers were a part of the Ghaznavid army and the 14th-century Muslim scholar Ibn Battuta took meaning of the Hindu Kush as the "slayer of Indians", because large numbers of slaves brought from India died from its treacherous weather.
The geographer Ya'qubi states that the rulers of Bamiyan, called the Sher, converted in the late 8th century. Ya'qub is recorded as having plundered its pagan idols in 870 while a much later historian Shabankara'i claims that Alp-Tegin obtained conversion of its ruler in 962. No permanent Arab control was established in Ghur and it became Islamised after Ghaznavid raids. By the time of Bahram-Shah, Ghur was converted and politically united.
The Pashtun habitat during their conquest by Mahmud was located in the Sulaiman Mountains in the south of Afghanistan. Prior to Pashtun settlement in the Kabul River valley, Tajiks formed the dominant population of Kabul, Nangarhar, Logar and Laghman in east Afghanistan.Harlan 1939:127 The Pashtuns later began settling westward from Sulaiman Mountains in the south, and displaced or subjugated the indigenous populations such as Tajiks, Hazaras, the Farsiwanis, Nuristanis and Pashayi people before or during 16th and 17th centuries.
Before their conversion, the Nuristanis or Kafir people of Kafiristan practiced a form of ancient Hinduism infused with locally developed accretions. The region from Nuristan to Kashmir was host to a vast number of "Kafir" cultures. They remained politically independent until being conquered and converted under Afghan Amir Abdul Rahman Khan in 1895–1896.
Arab conquests and rule
During the Muslim conquest of Persia, the Arabs were drawn eastwards from the Iraqi plains to central and eastern Persia, then to Media, into Khorasan, Sistan and Transoxiana. 15 years after the Battle of Nahāvand, the Arabs controlled all Sasanian domains except some parts of Afghanistan, Tabaristan and Makran. Nancy Dupree states that advancing Arabs carrying the religion of Islam easily took over Herat and Sistan, but the other areas often revolted and converted back to their old faiths whenever the Arab armies withdrew. The harshness of the Arab rule caused the native dynasties to revolt after the Arab power weakened like the Saffarids founded by the zealous Yaqub who conquered many cities of the region.Dupree, Nancy (1971) "Sites in Perspective (Chapter 3)" An Historical Guide To Afghanistan Afghan Tourist Organization, Kabul, OCLC 241390 Historian Cameron A. Petrie states that while the Arab expansion had both social and religious motives, it was their extraction of taxes from the subjugated people that invited the numerous local rebellions.
Medieval Islamic scholars divided modern-day Afghanistan into two regions – the provinces of Khorasan and Sistan. Khorasan was the eastern satrapy of the Sasanian Empire, containing Balkh and Herat. Sistan included a number of Afghan cities and regions including Ghazni, Zarang, Bost, Qandahar (also called al-Rukhkhaj or Zamindawar), Kabul, Kabulistan and Zabulistan.
Before Muslim rule, the regions of Balkh (Bactria or Tokharistan), Herat and Sistan were under Sasanian rule. Further south in Balkh region, in Bamiyan, indication of Sasanian authority diminishes, with a local dynasty apparently ruling from the late antiquity, probably Hephthalites subject to the Yabgu of Western Turks. While Herat was controlled by Sasanians, its hinterlands were controlled by northern Hephthalites who continued to rule the Ghurid mountains and river valleys. The Arab Umayyads regularly claimed nominal overlordship over the Zunbils and Kabul Shahis, and in 711 Qutayba ibn Muslim managed to force them to pay tribute. They would also be conquered by the Saffarids and Ghaznavids.
In Afghanistan, the frontier of the Islamic conquest had become more or less stationary by the end of the first century of Hijri calendar. One reason was that the relative importance of Sistan and Baluchistan had begun to diminish by the time of Mu'awiya I, when the conquests of Bactria and Transoxiana were undertaken. In addition, the conquest in the eastern direction was extended to Makran and Sind, with Muslim colonies becoming established there in 711–12.
Sistan
The earlier Arabs called Sistan as Sijistan, from the Persian word Sagestan. It is a lowland region, lying round and eastwards from the Zarah lake, which includes deltas of Helmand and other rivers which drain into it. The Muslim conquest of Sistan began in 23 AH (643-644 AD) when Asim bin Amr and Abdallah ibn Amir invaded the region and besieged Zaranj. The Sistanis concluded a treaty with Muslims, mandating them to pay the kharaj.
The cash-strapped Sasanian king Yazdegerd III who had a large retinue, had fled to Kerman in 650. He had to flee from Kerman to Sistan after his arrogance angered the marzban of the place, eluding an Arab force from Basra which defeated and killed the marzban. Yazdegerd lost the support of governor of Sistan after demanding taxes from him and had to leave for Merv. It is not known whether this governor was a Sasanian prince or a local ruler at that time. The Arabs had campaigned in Sistan a few years earlier and Abdallah b. Amir had now gone in pursuit of Yazdegerd. He arrived in Kirman in 651 and sent a force under Rabi ibn Ziyad al-Harithi to Sistan.
Rabi crossed the desert between Kirman and Sistan, reaching the fortress of Zilaq which was within five farsangs of the Sistan frontier. The fort was surrendered by its dihqan. The fortress of Karkuya, whose fire temple is mentioned in the anonymously authored Tarikh-e-Sistan, along with Haysun and Nashrudh, surrendered to Rabi. Rabi then encamped in Zaliq and projected the seizure of Zarang, which though had earlier submitted to Arabs, needed to be subdued again. Although its marzban Aparviz put up a strong resistance, he was forced to surrender.
The Zaranj forces had received heavy casualties during the battle with Arab forces and were driven back to the city. According to sources, when Aparviz appeared before Rabi to discuss the terms, he found the Arab general was sitting on a chair made out of two dead soldiers and his entourage had been instructed to make seats and bolsters in the same fashion. Aparviz was terrified into submission and wished to spare his people of this fate. A peace treaty was concluded with payment of heavy dues. The treaty mandated one million dirhams as annual tribute, in addition to 1,000 slave boys bearing 1,000 gold vessels. The city was also garrisoned by Rabi.
Rabi thus succeeded in gaining Zarang with considerable difficulty and remained at the place for several years. Two years later, the people of Zarang rebelled and expelled Rabi's lieutenant and garrison. Abdallah b. Amir sent 'Abd ar-Rahman b. Samura to take back the city, who also added Bust and Zabul to Arab gains. 'Abd ar-Rahman besieged Zaranj and after the marzban surrendered, the tribute was doubled. The tribute imposed on Zarang was 2 million dirhams and 2,000 slaves.
During the period of the first civil war in the Arab caliphate (656–661), rebels in Zarang imprisoned their governor while Arab bandits started raiding remote towns in Sistan to enslave people. They gave in to the new governor Rib'i, who took control of the city and restored law and order. 'Abdallah b. Amir was made the governor of Basra and its eastern dependencies again from 661 to 664. Samura was sent back to Sistan in 661. An expedition to Khorasan was sent under him that included reputed leaders like Umar b. 'Ubaydillah b. Ma'mar, 'Abdullah b. Khazim, Qatariyy b. al-Fuja'a and Al-Muhallab ibn Abi Sufra. Samura reconquered Zarang, while also conquering the region between Zarang and Kisht, Arachosia, Zamindawar, Bust and Zabul.
Ziyad ibn Abihi was appointed governor of Basra in 664 and was also made governor of Kufa and its dependencies in 670, making him the viceroy of the entire eastern half of the Islamic empire. He sent his kinsman Ubaydallah b. Abi Bakra to destroy the Zoroastrian fire temples in Fars and Sistan, confiscate their property and kill their priests. While the fire temple of Kariyan was destroyed, the one at Karkuya survived along with its herbad. Ziyad's son Abbad was appointed governor of Sijistan by Mu'awiya I in 673 and served until 681. During the course of his governorship, the province apparently remained stable and Abbad led an eastward expedition which brought Kandahar to the caliphate. Caliph Yazid I replaced Abbad with his brother Salm, who was already governor of Khurasan.
Khorasan
There is general agreement among Arabic sources that Khorasan's conquest began in the reign of Uthman under Abdallah b. Amir, who had been appointed the governor of Basra (r. 649–655). Sayf's tradition however disagrees with this, dating it to 639 under the reign of Umar with Ahnaf ibn Qais leading the expedition. Al-Tabari meanwhile relates that Ahnaf's conquests occurred in 643. This could be because of confusion of Ahnaf's later activities under Ibn Amir and an attempt to magnify his role in Khorasan's conquest.
The conquest of southern Persia was completed by 23 AH with Khorasan remaining the only region remaining unconquered. Since the Muslims did not want any Persian land to remain under Persian rule, Umar ordered Ahnaf b. Qais to march upon it. After capturing the towns of Tabas and Tun, he attacked the region's easternmost city Herat. The Persians put up stiff resistance but were defeated and surrendered. A garrison was deployed in the city, while a column was detached which subjugated Nishapur and Tus. Umar had dispatched Ahnaf with 12,000 men from Kufa and Basra after Yazdegerd who had fled to Merv. After the Arabs arrived there, Yazdegerd fled to Marw al-Rudh from where he sent ambassadors to the Khakan of the Turks, the ruler of Soghd and the Chinese emperor, asking for their assistance. Yazdegerd later fled to Balkh, where he was defeated by the Arabs and fled across Oxus River.