Qays

Qays ʿAylān (Arabic: قيس عيلان), often referred to simply as Qays (Kais or Ḳays) were an Arab tribal confederation that branched from the Mudar group. The tribe may not have functioned as a unit in pre-Islamic Arabia (before 630). However, by the early Umayyad Caliphate (661-750), its constituent tribes consolidated into one of the main tribal political factions of the caliphate.

The major constituent tribes or tribal groupings of the Qays were the Ghatafan, Hawazin, Amir, Thaqif, Sulaym, Ghani, Bahila and Muharib. Many of these tribes or their clans migrated from the Arabian Peninsula and established themselves in Jund Qinnasrin, the military district of the northern region of Syria and Upper Mesopotamia, which long became their abode. From there they governed on behalf of the caliphs or rebelled against them. The power of the Qays as a unified group diminished with the rise of the Abbasid Caliphate, which did not derive its military strength solely from the Arab tribes. Nonetheless, individual Qaysi tribes remained a potent force and some migrated to North Africa and al-Andalus, where they carved out their power.

The full name of the tribal confederation is Qays ʿAylān or Qays ibn ʿAylān, though it is most frequently referred to simply as Qays; occasionally in Arabic poetry, it is referred to solely as ʿAylān. Members of the Qays are referred to as al-Qaysĭyūn (sing. Qaysī), transliterated in English-language sources as "Qaysites" or "Kaisites". As an ethno-political group, the Qays are referred to in contemporary sources as al-Qaysīyya. Unlike most tribes of Arabia, the sources seldom use the term Banū (literally "sons of") when referring to the descendants of Qays.

Qays is the namesake and progenitor of the confederation, and traditional Arab genealogy holds that the father of Qays was a certain Aylan. According to the traditional genealogists, ʿAylān was the epithet of al-Nās, a son of Mudar ibn Nizar ibn Ma'ad ibn Adnan. The theory that Aylan is the father of Qays is rejected by Ibn Khaldun (d. 1406), a medieval historian of Arab tribes, and is indirectly rejected by other medieval Arab historians. Rather, Ibn Khaldun asserts that "Qays Aylan" is the epithet of al-Nas ibn Mudar ibn Nizar ibn Ma'ad ibn Adnan. These historians hold varying theories as to the origins of the "Aylan" part of the epithet; among these are that Aylan was either the name of al-Nas's famous horse, his dog, his bow, a mountain where he was said to have been born, or a man who raised him.

Qays was one of the two subdivisions of Mudar, the other being the Khindif (also known as al-Yās). As descendants of Mudar, the Qays are considered Adnanites or "North Arabians"; Arab tradition traces the descent of all Arab tribes to either Adnan or Qahtan, father of the "South Arabians". By the dawn of Islam in the mid-7th century, the descendants of Qays were so numerous and so significant a group that the term Qaysī came to refer all North Arabians.

The Qays consisted of several branches, which were divided into further sub-tribes. The first-tier divisions, i.e. the sons of Qays, were Khasafa, Sa'd and Amr.

From Khasafa descended the large tribes of Hawazin and Banu Sulaym, both of whose founders were sons of Mansur ibn Ikrima ibn Khasafa, and the Banu Muharib, whose founder was the son of Ziyad ibn Khasafa. The Hawazin was a large tribal grouping that included several large sub-tribes. Among them were the Banu Amir, whose progenitor was Amir ibn Sa'sa' ibn Mu'awiya ibn Bakr ibn Hawazin, and the Thaqif, whose progenitor was Qasi ibn Munabbih ibn Bakr ibn Hawazin. However, references to the Hawazin often excluded the Banu Amir and Thaqif, and were limited to the so-called ʿujz Hawāzin (the rear of Hawazin). The latter included the tribes of Banu Jusham, Banu Nasr and Banu Sa'd, all of whose founders were sons or grandsons of Bakr ibn Hawazin. The Banu Sulaym was divided into three main divisions, Imru' al-Qays, Harith and Tha'laba.

Sa'd's sons A'sur and Ghatafan each bore several sub-tribes. The largest sub-tribes of A'sur were the Banu Ghani, whose founder was a son of A'sur, and the Banu al-Tufawa, which consisted of the descendants of three other sons of A'sur, Tha'laba, Amir and Mu'awiya, who were half-brothers of Ghani; they were collectively called after their mother, al-Tufawa. The Bahila was the other large sub-tribe of A'sur, and its founders were the sons of a certain Bahila, who, at different times was the wife of two of A'sur's sons, Malik and Ma'n; there were many clans of the Bahila, the largest being the Banu Qutayba and Banu Wa'il. The largest sub-tribes of the Ghatafan were the Banu Dhubyan and Banu Abs, both of whose founders were sons of Baghid ibn Rayth ibn Ghatafan, and the Banu Ashja', whose founder was a son of Rayth ibn Ghatafan. From Banu Dhubyan came the Fazara, whose founder was a son of Dhubyan, and the Banu Murra, whose founder was a son of 'Awf ibn Sa'd ibn Dhubyan.