Pre-Islamic period Seleucid and Parthian period The Daylamites first appear in historical records in the late 2nd century BC, where they are mentioned by
Polybius, who erroneously calls them "
Elamites" () instead of "Daylamites" (). In the Middle Persian prose
Kar-Namag i Ardashir i Pabagan, the last ruler of the
Parthian Empire,
Artabanus V (r. 208–224) summoned all the troops from
Ray,
Damavand, Daylam, and
Padishkhwargar to fight the newly established Sasanian Empire. According to the
Letter of Tansar, during this period, Daylam, Gilan, and
Ruyan belonged to the kingdom of Gushnasp, who was a Parthian vassal but later submitted to the first Sasanian emperor
Ardashir I (r. 224–242).
Sasanian period . The descendants of Gushnasp were still ruling until in ca. 520, when
Kavadh I (r. 488–531) appointed his eldest son,
Kawus, as the king of the former lands of the Gushnaspid dynasty. In 522, Kavadh I sent an army under a certain Buya (known as
Boes in Byzantine sources) against
Vakhtang I of Iberia. This Buya was a native of Daylam, which is proven by the fact that he bore the title
wahriz, a Daylamite title also used by
Khurrazad, the Daylamite military commander who conquered
Yemen in 570 during the reign of
Khosrow I (r. 531-579), and his Daylamite troops would later play a significant role in the conversion of Yemen to the nascent
Islam. The 6th-century Byzantine historian
Procopius described the Daylamites as; :"barbarians who live...in the middle of Persia, but have never become subject to the king of the Persians. For their abode is on sheer mountainsides which are altogether inaccessible, and so they have continued to be autonomous from ancient times down to the present day; but they always march with the Persians as mercenaries when they go against their enemies. And they are all foot-soldiers, each man carrying a sword and shield and three javelins in his hand (De Bello Persico 8.14.3-9)." The equipment of the Dailamites of the Sasanian army included swords, shield, battle-axe (
tabar-zīn), slings, daggers, pikes, and two-pronged javelins (
zhūpīn). Daylamites also took part in the siege of
Archaeopolis in 552. They supported the rebellion of
Bahrām Chōbin against
Khosrow II, but he later employed
an elite detachment of 4000 Daylamites as part of his guard. They also distinguished themselves at the
Yemeni campaign of Wahriz and in the battles against the forces of
Justin II.
Islamic period Resistance to the Arabs of Iran during the
Iranian Intermezzo. The Daylamites managed to resist the Arab invasion of their own mountainous homeland for several centuries under their own local rulers. Warfare in the region was endemic, with raids and counter-raids by both sides. Under the Arabs, the old Iranian fortress-city of
Qazvin continued in its Sasanian-era role as a bulwark against Daylamite raids. According to the historian
al-Tabari, Daylamites and
Turkic peoples were considered the worst enemies of the Arab Muslims. The
Abbasid Caliphate penetrated the region and occupied parts of it, but their control was never very effective. After Abbasid occupation of Tabaristan, The military success achieved by the Abbasids in
Daylam was not of practical benefit, as the rebels continued to attack the southern regions where the Abbasid garrisons were stationed. This prompted Caliph
al-Mansur to declare
jihad in 143 AH (
759/
760 CE) and sent messengers to
Basra and
Kufa to rally the people and call upon them to reinforce the army. The campaign was led by Muhammad ibn Abi al-Abbas, and when it reached
Mosul, fighters from Mosul and the
Jazira region in general joined it. However, this campaign and others achieved nothing in the Daylam region except for some spoils of war and captives that the soldiers were able to obtain during their skirmishes with the local population. Shortly after 781, the
Nestorian monk
Shubhalishoʿ began evangelizing the Daylamites and converting them to Christianity. He and his associates made only a little headway before encountering competition from Islam. During the reign of
Harun al-Rashid (r. 785–809), several
Shia Muslims fled to the largely pagan Daylamites, with a few Zoroastrians and Christians, to escape persecution. Among these refugees were some
Alids, who began the gradual conversion of the Daylamites to Shia Islam. Nevertheless, a strong Iranian identity remained ingrained in the peoples of the region, along with an anti-Arab mentality. Local rulers such as the
Buyids and the
Ziyarids, made a point of celebrating old Iranian and Zoroastrian festivals. The
Buyid amīrs, who were Daylamite themselves, supplemented their army of Daylamite infantrymen with Turkic cavalrymen. Daylamites were among the people comprising the
Seljuq army, and
Ghaznavids also employed them as elite infantry. Islamic sources record their characteristic painted shields and two-pronged short spears (in
zhūpīn; in
mizrāq) which could be used either for thrusting or for hurling as a javelin. Their characteristic battle tactic was advancing with a
shield wall and using their spears and battle-axes from behind. Zazas have long been identified as Daylamites by many scholars. The Zaza refer to themselves as Dimli or Dimla, which is derived from the word Daylam according to a linguistic theory introduced by
Friedrich Carl Andreas and supported by many other scholars later. At the same time, modern research suggests that the
Talysh have some cultural and linguistic connections with the historical Daylami people. In ancient times, the territory of the Talysh was called Deilem and it is possible that the Deilemites had a relationship with the Talysh. == Culture ==