Abd al-Qays was an ancient Arabian tribe from the Rabi`ah branch of the "North Arabian" tribes. In pre-Islamic times, the Abd al-Qays frequently raided Iran. When he became of age, Shapur II made it his first order of business to punish the Abd al-Qays. He led an army across the Persian Gulf and devastated large parts of Eastern Arabia and Syria, slaughtering most of the Abd al-Qays on the way. Later in his reign, Shapur moved many Abd al-Qays people to Kerman Province in Iran.
During the Arab conquest of Iran, the Abd al-Qays migrated to Iran in large numbers and carried out extensive raids in southern Iran. Sizable groups of them settled down in Tavvaz near Dalaki in Bushehr Province. In the early 700s, 4,000 Abd al-Qays warriors accompanied Qotayba on his campaign into Khorasan in Iran.
The Abd al-Qays were one of the inhabitants of the coast of Eastern Arabia, including Bahrain island. There are many gaps and inconsistencies in the genealogies of Abd al-Qays in Bahrain, thus Baharna are probably descendants of an ethnically mixed population. Bahraini society has traditionally divided itself into three genealogical categories in order: "ansab" (clear genealogies), "la ansab" (unclear genealogies) and "bani khudair" (foreigner). Baharna were "la ansab" because they have unclear genealogies.
Remnants of the tribe
- ʿABD-AL-QAYS Encyclopaedia Iranica.
- Brian John Ulrich (2007). "Constructing Al-Azd: Tribal Identity and Society in the Early Islamic Centuries". p. 107.
- "Iranians in Bahrain and the United Arab Emirates". Eric Andrew McCoy. pp. 70–71.