By Laurie McFarland Jackson ©2011
Sept... such an innocent, uncomplicated-sounding four letter word, but, as it turns out, a word that creates much discussion and interpretation. One list of sept names may be different from another. In this article you will find various bits of information about septs from a variety of sources. One thing you will discover... the word sept is anything but uncomplicated.
According to Wikipedia, the free encyclopedia, a sept is an English word for a division of a family, especially a division of a clan. The word might have its origin from Latin septum "enclosure, fold",  or it can be an alteration of sect 
The term is found in both Ireland and Scotland. It is sometimes used to translate the word slíocht, meaning seed, indicating the descendants of a person (i.e., Slíocht Brian Mac Diarmada, the descendants of Brian MacDermott).
In the context of Scottish clans, septs are families that followed another family's chief. These smaller septs would then make up, and be part of, the chief's larger clan. A sept might follow another chief if two families were linked through marriage. However, if a family lived on the land of a powerful laird or neighbor, they would follow him whether they were related or not. Bonds of man- rent were sometimes used to bind lesser chiefs and his followers to more powerful chiefs.
Historically, the term 'sept' was not used in Ireland until the nineteenth century, long after any notion of clanship had been eradicated. The English word 'sept' is most accurate referring to a subgroup within a large clan; especially when that group has taken up residence outside of their clan's original territory. (O'Neill, MacSweeney, and O'Connor are examples.) Related Irish septs and clans often belong to larger groups, sometimes called tribes, such as the Dál gCais, Uí Néill, Uí Fiachrach, and Uí Maine. Recently, the late Edward MacLysaght suggested the English word 'sept' be used in place of the word 'clan' with regards to the historical social structure in Ireland, so as to differentiate it from the centralized Scottish clan system. This would imply that Ireland possessed no formalized clan system, which is not wholly accurate. Brehon Law, the ancient legal system of Ireland clearly defined the clan system in pre-Norman Ireland, which collapsed after the Tudor Conquest. The Irish, when speaking of themselves, employed their term 'clan' which means "family" in Irish.
The site www.electricscotland.com suggests that the variety of surnames within a Scottish clan do not represent separate and definable sub-clans but instead reflect the vagaries of transition of the Gaels into the English naming system as well as marriages, migrations, and occupations. The main family itself may have developed a variety of surnames. The preferred modern usage is to avoid the use of the term “sept” and to simply describe these names as what they are – surnames of the family and of allied or dependent families. It is preferable to speak of “the names and families of Clan X” rather than to call a name “a sept of Clan X.” “Sept” is actually a term borrowed from Irish culture in the nineteenth century to explain the use of a variety of surnames by members of a single clan. Where Scots would say, ―MacGregor and his clan, “an Irish historian might say, ―O‘Neill and his sept.”
ElectricScotland’s short list of septs of Clan MacFarlane include the following families: Allan, Allanson, Bartholomew, Caw, Galbraith, Griesck, Gruamach, Kinnieson, Lennox, MacAindra, MacAllan, MacCaa, MacCause, MacCaw, MacCondy, MacEoin, MacGaw, MacGeoch, Macgreusich, Macinstalker, MacIock, MacJames, Mackinlay, MacNair, MacNeur, MacNider, MacNiter, MacRob, MacRobb, MacWalter, MacWilliam, Miller, Monach, Napier, Parlane, Robb, Stalker, Thomason, Weaver, Weir.
Macfarlane surnames listed in the Family Tree DNA Project (http://www.familytreedna.com) include the following:
Allan, Allanach, Allanson, Allison, Arrell, Arrol, Barclay (in Ulster), Bart, Bartholomew, Bartie, Bartson, Black*, Brice, Bryce, Caa, Callander, Caw, Condey, Condeyie, Condy, Cunnison, Galloway (in Stirling), Grassick (in Montrose), Grassie (in Aberdeen), Greusaich, Griesch (in Aberdeen), Grua- mach, Kennson, Kinnieson, Kinnison, Knox, Leaper, Lechie, Lennox, MacAindra, MacAllan, MacAllen, MacAndrew, MacAndro (in Dunbarton), MacCaa, MacCause, MacCaw, MacCondey, MacCondeyie, MacCondy, MacEach, MacEachern, MacEoin, MacErrachar, MacErracher, MacFarlan, MacFarland, MacFarlane, MacFarquahar, Macferlant (in Poland), MacGaw, MacGeoch, MacGilchrist, MacGreusach, MacGreusich, MacInally, MacInstalker, MacIock, MacJames, MacJock, MacKindlay, MacKinlay, MacNair, MacNaiyer, MacNayer, MacNeur, MacNider, MacNiter, MacNoyer, MacNuyer, MacRobb, MacWalter, MacWilliam, McFarlan, McFarland, McFarlane, Michie, Millar, Miller (in Dunbarton), Monach, Monachock, Nacfaire (in France), Parlan, Robb, Smith (in Dunbarton), Spruell, Stalker, Thomason, Thomson, Weaver, Webster, Weir, Williams, Williamson, Wilson, Wylie, Wyllie.
*Due to recent DNA results, the Admin team at FamilyTreeDNA have added the Black surname to the list of Septs. Four men with that surname are part of the main MacFarlane lineage, and their markers date back to before the 1600s. Although the Black surname is listed with three other clans, at least this one branch belongs with the MacFarlanes.
James Macfarlane wrote the History of Clan Macfarlane in 1922, (ISBN 978-1-152-95118-1.) At the time of 1846, “the lineal representative of the ancient and honourable house of Macfarlan and that ilk...” included the following families:
Arrell, Arrol, Allan (also Clan Ranald), Allanson (also Clan Ranald), Allanach (also Clan Ranald), Bartholomew, Barclay, Caw, Griesch (Aberdeen), Grassie (Aberdeen), Grassick (Montrose), Gruamach, Galloway (Stirling),Kinnieson, Kennson, Kinnison, Mac Allan (also ClanRanald, MacKay and Stewart),MacAindra, MacAndrew, MacAndro (of Dumbartonshire), MacCaa, MacCause (Thomson), MacCaw (also Stewart of Bute), MacCondey, MacEoin, MacEachern (also an ancient race of Kintyre and Criagnish), MacErracher, MacGaw, MacGeoch, Macgreusich (also Buchanan), MacInstalker, MacJock, MacJames, Mackinlay, MacNair (also McNaughton), MacNeur, MacNuyer (also Buchanan and Mcnaughton), MacNider, MacNiter, MacRob (also Gunn), MacRobb, MacWalter, MacWilliam (also Gunn), Miller (of Dumbartonshire), Michie, Monach, Parlane, Robb, Stewart, Stalker , Weaver, Wilson, Weir, Williamson, Galbraith, Lennox, Napier
James continues his description of the septs of Macfarlane in great detail. There were many Macfarlanes in the north and west Highlands, especially in the counties of Dumbarton, Perth, Stirling, and Argyle; also in the shires of Moray and Inverness, and the western isles. Northern Ireland was also home to many Macfarlanes.
There are a large number of descendants from, and dependents on, the Macfarlane surname and family. The largest group of these descendants is the Allans or Macallans. It began with Allan Macfarlane, a younger son of one of the Chiefs of Arrochar who went to the north and settled there several centuries ago. Allan‘s sons called themselves sons of Allan instead of taking the family name of Macfarlane. So, Allanson and Allanach are variations of Macallan.
In another case, the sons of Thomas, younger son of Duncan, the 6th Chief, called themselves Thomas’ sons instead of Macfarlane.
―There are also Macnairs, Maceoins, Macerrachers, Macwilliams, Macaindras, Macniters, MacInstalkers, Macjocks, Parians, Farlans, Graumachs, Kinniesons, etc., all which septs acknowledge themselves to be Macfarlanes, together with certain septs of Macnayers, Mackinlays, Macrobbs, Macgreusichs, Smiths, Millers, Monachs, and Weirs.
Clans & Tartans of Scotland by James Mackay (Gramercy Books New York, 2000, ISBN 0-5 17- 16240-7) begins an explanation of septs starting in the thirteenth and fourteenth centuries as surnames were gradually adopted in Scotland. In its most pure form, the clan was essentially a family group with members that traced their roots back to a common ancestor and who were thereby linked by blood ties. It included illegitimate children, as well as children fostered or adopted by the family. It would also include the children of women who had married outside the family group and who, therefore, had a different surname. More commonly, however, the appearance of other surnames within the clan came from landless men or outlaws attaching themselves to the clan for protection, giving service in return. From this arose the idea of the sept. This word, derived from the Latin septum, an enclosure or fence, alludes to the fact that, originally, a particular plot of clan land was set aside for these landless followers where they could establish a village of their own.
Following the Jacobite Rebellion of 1745-46 the age-old allegiance of the clansman to his chief was eventually replaced by the ties of kindred, in which the possession of a common surname became of utmost importance. A person‘s surname gives a sense of identity, but in the Scottish system it also gives a feeling of solidarity that nowadays links people from all around the globe and from every walk of life. The ties that bind us may be extremely tenuous, but the name is all-important. The spread of Scottish clan names to every part of the world is a reflection of the Scottish diaspora (a dispersion of a people, language, or culture that was formerly concentrated in one place.) Thirty million people who are of Scottish descent have been estimated to live outside Scotland - that is six times the number of people actually living in Scotland. Pride in bearing a Scottish surname has not only strengthened the bonds of expatriates, but has also helped to keep alive a sense of Scottish nationhood over the past three centuries.
S-E-P-T... a deceptively complicated four-letter word... a word that means family.