Many Iraqi Arabs identify strongly with a tribe (العشيرة 'ashira). 30 of the 150 or so identifiable tribes of Iraq are the most influential. They are grouped into federations (قبيلة qabila). Within the tribe, there is the clan (الفخذ fukhdh), the house (البيت beit) and the extended family (الخمس khams). Tribes are led by sheikhs (شيخ sheykh) who represent the tribe and deal with its domestic affairs. Due to the large sizes of Iraq's tribes, an individual may belong to the Shammar tribe, but also the Aslam branch within the same tribe, and therefore can identify with both. There are hundreds of Arab tribes across Iraq from the north to the south.
On its accession to power in the 17 July Revolution of 1968, Iraq's Ba'ath Party announced its opposition to tribalism ( القبلية ''al-qabaliyya''), although for pragmatic reasons, especially during the Iran–Iraq War, tribalism was sometimes tolerated and even encouraged.