The battle was fought in Farney in 331 AD according to the
Annals of the Four Masters. In later sections of the Annals, Farney is spelt 'Fernmaighe' in the
Gaelic language and 'Fearnmaighe' in the English translation. Two baronies of county Monaghan, whose histories are deeply entangled, lay claim to "Farney", namely Dartree and Farney. The present county of Monaghan, in the early medieval era was part of the more extensive kingdom of Mugdorna - the tribe of Mugdornai: from which the barony of Cremorne derives its name. In this period Fernmhagh was centred in north west Monaghan around
Loch Uaithne - Lough Ooney. The Annals of the Four Masters (for the year 849) say that "Caireall, son of Ruadhrach, lord of Lough Uaithne, was slain by the Conaille." A footnote by O'Donovan describes Lough Ooney as follows:
Peadar Livingstone, in
The Monaghan Story, states Also from the same publication Livingstone further states: The preserving of a name that formerly belonged to another place is an occurrence frequent in Irish topography.
Twelfth century expansion and migration By the late 11th century the airgillia kingdom of Ui Chremthainn was controlled by the leading family of the Fir Fernmaige, using the surname of Ua Cerbaill. Due to
Cenél nEógain pressure the Ui Chremthainn power base which had centred on
Clogher was shifting south west into Monaghan. By early in the twelfth century the Ua Cerbhaill under the powerful political and religious reformer - King Donnchadh ua Cerbhaill controlled the ancient lands of the mugdornai. Donnchadh ua Cerbhaill (O'Carroll) endowed the establishment of
Mellifont Abbey and under his kingship the airgillia federation would play an immense role in twelfth century developments in Ireland. As the twelfth century progressed the Ua Cherbaill expansion continued south easterly and their power base shifted from Clogher. Contemporary with this shift may have been the relocation of the ~ "
Fir Fernmaighe" - Farney, from their original historically associated location of Lough Uaithne/Ooney into the south east region of modern Monaghan which now is known as the barony of Farney. The
Dioceses established at the
Synod of Ráth Breasail laid sold foundation for church establishment but many changes had occurred in the decades following as ua Cherbhaill expansion continued into
County Louth, Donnchadh ua Cerbhaill instigated the bishop of Louth or Airgillia, while that of the
Bishop of Clogher temporarily fell into disuse. ==After the battle - The disputed Sites==