Vendetta

Vendetta
A fortified tower used as refuge for men involved in a blood feud that are vulnerable to attack. Thethi, northern Albania.Originally, a vendetta was a blood feud between two families where kinsmen of the victim intended to avenge his or her death by killing either those responsible for the killing or some of their relatives. The responsibility to maintain the vendetta usually falls on the closest male relative to whoever has been killed or wronged, but other members of the family may take the mantle as well. If the culprit had disappeared or was already dead, the vengeance could extend to other relatives.
Vendetta is typical of societies with a weak rule of law (or where the state doesn't consider itself responsible for mediating this kind of dispute) where family and kinship ties are the main source of authority. An entire family is considered responsible for whatever one of them has done. Sometimes even two separate branches of the same family could come to blows over some matter.

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http://en.wikipedia.org/wiki/Vendetta