What was the structure of the tribes at the time of the Prophet(saw)?

n a Nutshell: In 7th-century Arabia, there was no centralized state, police force, or overarching judicial system. The fundamental building block of society was the tribe. A person’s physical safety, economic survival, and social standing depended entirely on their tribal affiliation and the ability of their kin to protect them or seek vengeance on their behalf. The Foundation of Society: Kinship and Alliances Arabian society was strictly agnatic (patrilineal), meaning lineage and tribal belonging were traced exclusively through the father's bloodline. This created a powerful sense of tribal solidarity known as 'Asabiyyah. Because survival depended on numbers and strength, tribes operated as "co-liable groups." If a member of a clan was killed, the entire clan was obligated to seek blood vengeance (qisas) or exact blood money (diyah). Conversely, if a member committed a crime, the entire clan was financially liable to pay the penalty. However, blood relations were not the only way to build these groups. Tribes frequently utilized complex alliances (Ahlaf) to bind non-relatives into their co-liable group. This allowed smaller clans to attach themselves to more powerful ones for protection, or for multiple clans to unite for specific military or economic aims. The Seven Tiers of Lineage (Nasab) Classical scholars of Arabian lineage (nasab) and lexicographers later categorized the complex web of Arab tribes into a formalized, seven-tier system. While 7th-century Arabs may have used these terms somewhat interchangeably in daily life, genealogists agree that each category represented an independent socio-political entity that fell under a larger one. From largest to smallest, the seven strata are: Sha'b (شَعْب - Nation/Confederacy): The original, vast substance of a lineage going back to a remote, ancient ancestor. For the Northern Arabs, this was Adnan; for the Southern Arabs, it was Qahtan. It is called Sha'b (similar to "people") because all subsequent lineages branch out (yatasha'ab) from it. Qabeelah (قَبِيلَة - Tribe): The primary tribal identity, derived from one of the descendants of the Sha'b. A Qabeelah (e.g., Kinanah, Hawazin, Azd) was a massive, independent social, economic, and political entity with its own distinct loyalties, armies and territories. Imarah (عِمَارة - Sub-Tribe / Major Clan): A large subdivision of the Qabeelah. The famous historian Ibn Manzhur defined it as a "great independent quarter" capable of having its own camps and settlements. They were large enough to engage in independent political contracts, provided they did not harm the overarching Qabeelah. Battn (بَاطِن - Clan; plural: Butun): The core socio-political unit of daily life. The Battn was the primary entity responsible for managing internal affairs and Shari'ah rulings, such as the collection and payment of blood money (diyah). Fakhdh (فَخْذ - Sub-Clan; plural: Afkhadh): A subdivision of the Battn. A Fakhdh could act as an independent political entity during internal tribal disputes or boycotts. Ashirah (عَشِيرَة - Extended Family / Kinsmen): The close relatives of a man's father. This term often refers to a person's immediate uncles and paternal cousins, though it was sometimes used broadly to refer to the Fakhdh. Faseelah (فَصِيلَة - Immediate Family): The smallest unit, consisting of the immediate household, sons, and daughters of a specific patriarch. The Fluidity of the System It is important to note that these categories were relative. Depending on how far back in history one looked, a group that was once a small family could grow over centuries into a massive confederacy. The 11th-century leading genealogist Al-Mawardi perfectly summarized this fluid reality: "When the lineages become distant, the Qaba'il [Tribes] become Shu'ub [Nations]; the Ama'ir[Sub-tribes] become Qaba'il; the Butun [Clans] become Ama'ir; the Afkhadh[Sub-clans] become Butun; and the Fasa'il [Families] become Afkhadh." (Al-Qalqashandi, Qala'id al-Juman)