A Cain is the fundamental political and social community of the Skyre Folk. Cains are often described as tribes, but each is more than a single extended family. A Cain carries a shared name, history, customs, relationships with particular territories and sacred places, and a continuing network of obligations among its members. Most are semi-nomadic, moving through familiar regions rather than concentrating the entire community in one permanent settlement.
Each Cain governs itself. Its secular leader is selected by respected elders from among people considered suitable to lead, but the standards for eligibility and the manner in which the elders reach their choice vary from Cain to Cain. Some may emphasize experience in diplomacy or war, others knowledge of particular territories, long service to the community, family standing, or qualities defined by local custom. There is no single rule of succession shared by all Skyre Folk.
The secular leader is responsible for practical leadership, defense, diplomacy, and ordinary political decisions. The Athair, always a priestess, serves separately as the senior spiritual and druidic authority. Neither office is subordinate to a central Skyre government, and the balance between leader, Athair, elders, and other respected members is shaped by the customs of the individual Cain.
Cains cooperate when their interests overlap, and matters affecting many of them may lead to a Moot. Such cooperation does not erase their independence. A Moot creates common action through negotiated commitments accepted by the participating Cains rather than through a permanent authority empowered to govern them.
The best-known Cains include Cain Tiarnach, Cain Carthaigh, Cain Earnan, Cain Seanain, Cain Cailean, Cain Ciardha, Cain Braoin, Cain Feme, and Cain Moen. Most are associated with the Skyre Islands, while Cain Moen is associated with the southern shores of Aesala, demonstrating that Skyre identity is not limited to the archipelago.