active in Roman Britain, one piece of evidence being the name of their capital Cashel, thought to be inspired by the Roman castella they observed on raids. The Déisi Muman enjoyed a position in the later Eóganachta overkingdom suggesting of a special relationship. Byrne mentions it was noticed by Eoin MacNeill that a number of the early names in the Eóganachta pedigrees are found in oghams in the Déisi country of Waterford, among them Nia Segamain (NETASEGAMONAS), after the Gaulish war god Segomo. According to MacNeill, the Waterford Déisi and the Eóganachta at Cashel "cannot well be disconnected". The Uí Liatháin dynasty were western neighbors of the proto-Déisi Muman along the southern Irish coast and raided and colonized parts of Wales and Cornwall. They are the best characterized of the South Irish colonists because of clear references to them by name in both early Irish and early British sources, while a presence of the Déisi Muman cannot actually be confirmed. Also noted are the Laigin, particularly in North Wales. Possible presence in Britain The Déisi Muman are the subjects of one of the most famous medieval Irish epic tales, The Expulsion of the Déisi. This literary work, first written sometime in the eighth century, is a pseudo-historical foundation legend for the medieval Kingdom of Déisi Muman, which seeks to hide the historical reality that the kingdom's origins lay among the indigenous tributary peoples of Munster. To this end it attributes to "the Déisi" an entirely fictive royal ancestry at Tara. The term "Déisi" is used anachronistically in The Expulsion of the Déisi, since its chronologically confused narrative concerns "events" that long predate the historical development of déisi communities into distinct tribal polities or the creation of the kingdom of Déisi Muman. The epic tells the story of a sept called the Dal Fiachach Suighe, who are expelled from Tara by their kinsman, Cormac mac Airt, and forced to wander homeless. After a southward migration and many battles, part of the sept eventually settles in Munster. At some point during this migration from Tara to Munster, one branch of the sept, led by Eochaid Allmuir mac Art Corb, sails across the sea to Britain where, it is said, his descendants later ruled in Demed, the former territory of the Demetae (modern Dyfed). The Expulsion of the Déisi is the only direct source for this "event". The historicity of this particular passage