This is a list of battles recorded in the Annals of the Four Masters, written in the 17th century, as taking place in prehistoric Ireland. Many of the battles listed are purely mythological, and none are historically reliable. Other Irish annalistic and chronicle sources differ in their chronologies.
Reign of Ceasair, 2242-???? - No warfare.
Reign of Parthalon, 2520–50
2530 - Magh Ithe, first recorded battle in Ireland.
Reign of Neimhidh, 2850–59
Murbholg, in Dál Riata
Baghna
Cnamh Ross
Reign of Eochaidh mac Erc, 3294-3304.
3304 - First Battle of Magh Tuireadh, in Conmaicne Toland.
Reign of Nuadhat Airgeatlamh, 3311-30.
3330 - Second Battle of Magh Tuireadh
Reign of Lugh Lamhfhada, 3330-3370.
3370 - Caendruim.
Joint-Reign of Mac Cuill, Mac Cecht, and Mac Greine, 3471-3500.
3500 - Sliabh Mis, Tuatha de Danann defeated by the sons of Milidh
3500 - Tailtinn.
Joint-Reign of Eremhon and Emher, 3501.
3501 - Geisill, fought at Tochar Eter Da Mhagh near Bri Damh
Reign of Eremhon 3502-16.
3502 - Cuil Caichir
3503 - Biletineadh
3506 - Breogan, in Feimhin
3510 - Comhraire, in Meath
Joint Reign of Muimhne, Luighne, Laighne, sons of Eremon, 3517-19.
3519 - Ard Ladhron
Joint-Reign of Er, Orba, Fearon, Fergen, sons of Emher, first half of 3519.
3519 - Cuil Marta
Reign of Irial Faidh, 3519-329.
Ard Inmaoith, in Teathbha
Tenmaighe
Lochmaighe
Reign of Conmael 3549-79.
3549 - Raeire
Geisill
Berra
Sliabh Beatha, in Ui Creamhthainn
Ucha
Cnucha
Sliabh Modhairn
Clere
Carnmor
Loch Lein
Ele
3579 - Aenach Macha
Reign of Tighearnmas, 3580-3656.
Elle
Lochmagh
Cul Ard, in Magh Inis
Cuil Fraechan
Magh Techt
Commar
Cul Athguirt, in Seimhne
Ard Niadh, in Connaught
Carn Fearadhaigh
Cnamh Choill, in Connaught
Cuil Feadha
Reabh
Congnaidhe, Tuath Eabha
Cluain Cuas, in Teathbha
Cluain Muirsge, in Breifne
Two Battles of Cuil, in Argat Ross
Ele
Berra
Seven Battles of Loch Lughdhach
Two Further Battles of Argat Ross
Three Battles of the Firbolgs
Cuil Fothair
Reign of Eochaidh Eadghadhach, 3664-67.
3667 - Teamhair
Joint-Reign of Sobhairce and Cearmna Finn, sons of Ebric mac Emher: 3668-3707.
Reign of Eochaidh Faebhar Ghlas mac Conmael: 3708-3727.
Luachair Deadhadh
Fosadh Da Ghort
Comar Tri nUisge
Tuaim Drecon, in Ui Briuin Breifne
Druim Liathain
3727 - Carman
Reign of Fiacha Labhrainne: 3728-51.
Gathlach
Fairrge
Sliabh Feimhin
Magh Ernai
3751- Bealgadan
Reign of Eochaidh Mumho mac Mofebis: 3752-72.
3772 - Cliach
Reign of Aengus Olmucadha mac Fiacha Labhrainne: 3773-90.
Clere
Cuirce
Sliabh Cailge, in Corca Bhaiscinn
Ros Fraechan, in Muirisc
Carn Riceadha
Cuil Ratha, in South Munster
Sliabh Cua
Ard Achadh
Fifty Battles of the Cruithean Tuath and Firbolgs
Twelve Battles of the Longbardai
Four battles of the Colaisti
3790 - Carmann
Reign of Enna Airgtheach: 3791-3817.
3817 - Raighne
4815 - Tara.
4907 - Ard Crimhthainn.
5089 - Aillinn.
5090 - Cliach, in Ui Drona.
5160 - Bruighean Da Dhearg
76 - Aichill
106 - Moin An Chatha, in Magh Line, Dal Araidhe.
122 - Magh hAgha
157 - Tuath Amrois.
186 - Ceannfeabhrat.
195 - battle of Maigh Mucruimhe.
226 - Crinna, in Brega.
236 - Eu, Magh nAi.
236 - Eth.
236 - Ceann Daire.
236 - Sruth.
236 - Slighe Cuailgne.
237 - Ath Beatha
237 - Dumha
238 - Three Battles of Cuiltochair.
238 - Three Battles of Dubhadh.
239 - Allamagh
239 - Seven Battles of Elve
240 - Magh Techt
241 - Berre
241 - Loch Lein
241 - Luimneach
241 - Grian
241 - Classach
241 - Muiresc
241 - Fearta
241 - Samhain
241 - Ard Cam
241 - Massacre of Cleanfearta
248 - Fochard Muirtheimhne
262 - Crionna Fregabhail
265 - Seven Battles of the Desi
271 - Year of The Three Battles
272 - Year of The Four Battles
283 - Ath Brea, on the Boyne
284 - Gabhra Aichle
285 - Ollarba, in Magh Line
291 - Duibhlinn
291 - The Three Battles of Sliabh Toadh
291 - Smear
291 - Ciarmhagh
322 - Dubhchomar, in Crioch Rois, in Breagh
331 - Achadh Leithdheirg, in Fearnmhagh
356 - Portrigh
Prehistoric Irish battles Wikipedia (Text) CC BY-SA