kingdoms of ancient ireland

The earliest known kingdoms or tribes in Ireland are referred to in Ptolemy's 2nd century Geography. He names the Vennicni, Rhobogdi, Erdini, Magnatae, Autini, Gangani, Vellabori, Darini, Volunti, Eblani, Cauci, Menapii, Coriondi and Brigantes. Irish medieval pseudohistory gives a division of kingdoms which seems more ideal than real. The island is divided into "fifths" (Old Irish ciceda, Modern Irish cige): Ulaid (Ulster) in the north, Ol nEcmacht (Connacht) in the west, Mumha or Mhumhain (Munster) in the south, and Laighin (Leinster) in the east, around the central kingdom of Mde (whose name has survived in the modern counties Meath and Westmeath). Each of the outer four fifths had their own king, with the High King of Ireland ruling over them from Tara in Mde. In historical times Mde disappeared as a province. The four remaining fifths contained large numbers of tuatha or sub-kingdoms, constantly shifting as old dynasties died and new ones formed. Some known from historical sources are:

Ulster

Earliest times

Darini, in Tyrone, Armagh and Down, possibly a branch of the rainn and linked with their supposed ancestor deity Dire
Erdini in County Fermanagh
Robogdii, in Antrim and Londonderry, possibly related to the later Dl Riata
Venicnii in County Donegal
Voluntii, probably the people later known as the Ulaid, in Armagh, Down, Monaghan and Cavan

Early Christian

Meath

Earliest times

Ebdani, Eblani or Blanii (probably variants of the same name)

Early Christian

Cianachta
Southern U Nill

Leinster

Earliest times

Brigantes in south Wexford, also known from northern Britain; possibly linked with the goddess Brigit
Cauci around Dublin
Coriondi north Wexford, possibly related to the British Coritani
Menapii in County Wicklow, also known from Gaul; their name is linked to Fermanagh and Monaghan, although they are much further north