Sept

A sept is an English word for a division of a family, especially of a Scottish or Irish family. The word may derive from the Latin saeptum, meaning "enclosure" or "fold", or via an alteration of "sect". The term is used in both Ireland and Scotland, where it may be translated as sliocht, meaning "progeny" or "seed", which may indicate the descendants of a person (for example, Sliocht Brian Mac Diarmada, "the descendant of Brian MacDermott").

Síol is a Gaelic word meaning "progeny" or "seed" that is used in the context of a family or clan with members who bear the same surname and inhabited the same territory, as a manner of distinguishing one group from another; a family called Mac an Bháird (anglicised as "Ward") might be divided into septs such as Síol Seán Mac Briain, Síol Conchobhair Óg, Síol Sean Cuinn, or Síol Cú Chonnacht. Each of these individual septs may further subdivide into more septs, which may sometimes lead to the development of novel surnames and/or the rise of the family such that it may be considered a clan in its own right. Such septs were common in Scotland, where the clan system was well-developed.

In the context of Scottish clans, septs are families that followed another family's chief. These smaller septs would then comprise, and be part of, the chief's larger clan. A sept might follow another chief if two families were linked through marriage; or, if a family lived on the land of a powerful laird, they would follow him whether they were related or not. Bonds of manrent were sometimes used to bind lesser chiefs and his followers to more powerful chiefs.

Today, sept lists are used by clan societies to recruit new members. Such lists date back to the 19th century, when clan societies and tartan manufacturers attempted to capitalise on the enthusiasm and interest for all things Scottish. Lists were drawn up that linked as many surnames as possible to a particular clan. In this way, individuals without a "clan name" could connect to a Scottish clan and thus feel "entitled" to its tartan.

One modern member of the Lyon Court has described the attribution of such names to particular clans as sometimes being based upon nothing but imagination, and in others cases upon a single recorded instance of a surname.

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