My current writing project is a book on legal systems very different from ours, based on a seminar I have taught for some years at SCU; my current chapter drafts are webbed for a workshop I am doing at George Mason this fall.
The legal systems I have done chapters on so far include ancient Irish law (c. 6th century) and traditional Somali law. Surprisingly enough, they have several features in common. In both, one consequence of injuring someone is the legal obligation to provide your victim with sick-maintainance—hospitality and medical services until he recovers.
In the Irish system the kin-group called the fine, consisting of all descendants in the paternal line of a common great-grandfather, is responsible for seeing that its members pay any fines or damage payments they owe or, if they don't, paying for them. In the Somali system the kin-group called the juffo, consisting of all descendants in the paternal line of a common great-grandfather, is responsible for some but not all fines owed by its members, the rest being the responsibility of the jilib, a group of several related juffos.
All very suspicious. The Celts wandered pretty far but, so far as I know, they never made it to the horn of Africa. Looking at it from the other side there are people referred to as "black Irish," but I don't believe ... .