Bani Abdul Qais

The Abd al-Qays (Arabic: عبد القيس) is an ancient Arabian tribe from the Rabi'a branch of the North Arabian tribes. The tribe is from Eastern Arabia. The majority of the Baharna are from the Abd al-Qays tribe, with a significant minority from the cousin tribes of Bakr and Taghlib Ibn Wai’l tribes, which are today known as the Anizah tribe. The majority of the tribe resides today in the Gulf Cooperation Council countries, which are Kuwait, Saudi Arabia, Bahrain, Qatar, Oman and the UAE.

The name of the tribe means 'servant of the [god] Qays'. It belonged to the tribal groups originally resident in the area of al-Arid in South Arabia who migrated northwestward to an area extending north to Sudayr and south to al-Kharj. Later, in the Arab genealogical tradition, these tribes were called the Rabi'a, a branch of the northern Arab Ma'add confederation.

In pre-Islamic times, the Abd al-Qays frequently raided Iran. The Sasanian king Shapur II () led an expedition against the Arabian tribes, during which he massacred most of the Abd al-Qays. Later, several Abd al-Qays tribesmen were relocated by Shapur to the Iranian province of Kirman.

By the 5th century, the Abd al-Qays had shifted to nomadism, dwelling outside of the Tuwaiq escarpment in the southern Najd (central Arabia). In the 6th century, the tribe migrated northeastward the oases of al-Ahsa, Tarout Island and Qatif in eastern Arabia.