stylistic:style_transfer
Medieval period

Early Syriac sources use the terms Hurdanaye, Kurdanaye, Kurdaye to refer to the Kurds. According to Michael the Syrian, Hurdanaye separated from Tayaye Arabs and sought refuge with the Byzantine Emperor Theophilus. He also mentions the Persian troops who fought against Musa chief of Hurdanaye in the region of Qardu in 841. According to Barhebreaus, a king appeared to the Kurdanaye and they rebelled against the Arabs in 829. Michael the Syrian considered them as pagan, followers of mahdi and adepts of Magianism. Their mahdi called himself Christ and the Holy Ghost.

In the early Middle Ages, the Kurds sporadically appear in Arabic sources, though the term was still not being used for a specific people; instead it referred to an amalgam of nomadic western Iranian tribes, who were distinct from Persians. However, in the High Middle Ages, the Kurdish ethnic identity gradually materialized, as one can find clear evidence of the Kurdish ethnic identity and solidarity in texts of the 12th and 13th centuries, though, the term was also still being used in the social sense. Since 10th century, Arabic texts including al-Masudi 's works, have referred to Kurds as a distinct linguistic group. From 11th century onward, the term Kurd is explicitly defined as an ethnonym and this does not suggest synonymity with the ethnographic category nomad. Al-Tabari wrote that in 639, Hormuzan, a Sasanian general originating from a noble family, battled against the Islamic invaders in Khuzestan, and called upon the Kurds to aid him in battle. However, they were defeated and brought under Islamic rule.

In 838, a Kurdish leader based in Mosul, named Mir Jafar, revolted against the Caliph Al-Mu'tasim who sent the commander Itakh to combat him. Itakh won this war and executed many of the Kurds. Eventually, Arabs conquered the Kurdish regions and gradually converted the majority of Kurds to Islam, often incorporating them into the military, such as the Hamdanids whose dynastic family members also frequently intermarried with Kurds.

In 934, the Daylamite Buyid dynasty was founded, and subsequently conquered most of present-day Iran and Iraq. During the time of rule of this dynasty, Kurdish chief and ruler, Badr ibn Hasanwaih, established himself as one of the most important emirs of the time.

In the 10th–12th centuries, a number of Kurdish principalities and dynasties were founded, ruling Kurdistan and neighbouring areas:

Due to the Turkic invasion of Anatolia and Armenia, the 11th-century Kurdish dynasties crumbled and became incorporated into the Seljuk dynasty. Kurds would hereafter be used in great numbers in the armies of the Zengids. The Ayyubid dynasty was founded by Kurdish ruler Saladin, as succeeding the Zengids, the Ayyubids established themselves in 1171. Saladin led the Muslims to recapture the city of Jerusalem from the Crusaders at the Battle of Hattin; also frequently clashing with the Assassins. The Ayyubid dynasty lasted until 1341 when the Ayyubid sultanate fell to Mongolian invasions.