The Setantii (sometimes read as ''Segantii'') were a possible pre-
Roman Briton people who apparently lived in the western and southern
littoral of
Lancashire
Lancashire ( , ; abbreviated ''Lancs'') is a ceremonial county in North West England. It is bordered by Cumbria to the north, North Yorkshire and West Yorkshire to the east, Greater Manchester and Merseyside to the south, and the Irish Sea to ...
in
England
England is a Countries of the United Kingdom, country that is part of the United Kingdom. It is located on the island of Great Britain, of which it covers about 62%, and List of islands of England, more than 100 smaller adjacent islands. It ...
. It is thought likely they were a
sept or sub-tribe of the
Brigantes, who, at the time of the
Roman invasion, dominated much of what is now
northern England.
Background

The Setantii name is known from a single source only, the 2nd century ''
Geographia of
Ptolemy
Claudius Ptolemy (; , ; ; – 160s/170s AD) was a Greco-Roman mathematician, astronomer, astrologer, geographer, and music theorist who wrote about a dozen scientific treatises, three of which were important to later Byzantine science, Byzant ...
''. Recorded there is the
placename ''Portus Setantiorum'' (Port of the Setantii).
Its precise location remains unknown although various suggestions have been made, including the possibility that it has since been lost to the sea. Some scholars argue that it may have been located in present-day
Fleetwood.
Also recorded by Ptolemy is the
hydronym ''Seteia'', assumed by its position in his text to refer to the
River Mersey.
Links to later Celtic legends
Sir John Rhys linked the name of the Setantii with
Seithenyn, a figure in
Welsh mythology
Welsh mythology (also commonly known as ''Y Chwedlau'', meaning "The Legends") consists of both folk traditions developed in Wales, and traditions developed by the Celtic Britons elsewhere before the end of the first millennium. As in most of t ...
. Seithenyn was a prince with responsibilities over the sea defences of
Cantre'r Gwaelod
, also known as or , is a legendary ancient sunken kingdom said to have occupied a tract of fertile land lying between Ramsey Island and Bardsey Island in what is now Cardigan Bay to the west of Wales. It has been described as a "Welsh Atla ...
. Drunkenly neglecting his duties one night, the sea overran the kingdom, and it sank beneath
Cardigan Bay. Rhys noted the similarities between Setantii, Seithenyn, the
Irish Sétanta Beg, and the
Breton legends surrounding ''"
Enez-Sizun"'' and the
Lost City of Ys.
Rhys posited that, although the name was
Brythonic in origin, the
soundings of the later legends left no doubt that "we have in these names distant echoes of an
inundation story, once widely current in both Britains (Great Britain and Brittany) and perhaps also in Ireland". Although he acknowledged he was unaware of any similar legend on the Lancashire coast (such as the inundation of Portus Setantiorum), Rhys linked all the later legends back to the Setantii of Lancashire.
''Sétanta'', the birth name of the Irish legendary figure
Cú Chulainn, may also be linked to the Setantii.
References
Further reading
*
Celtic Britons
Historical Celtic peoples
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