Brythonic male names
The Brythonic peoples of Britain in our period were the remnants of the Romano-British inhabitants who had been slowly pushed to the western and northern fringes of the island by the arrival of the various Germanic peoples (Saxons, Jutes, Angles etc).
By the start of our period, in the late eighth century, the various Brythonic nations had been geographically separated from one another with Saxon kingdoms cutting off Wales, Cornwall and the northern Brythonic kingdoms off from one another. This separation began to manifest in language as well as culture, as seen by naming practices.
Names appearing here are taken largely from the Medieval Name Archive which has several well-researched articles on the subject. I have included only the Brythonic versions, not the Latin in which most of these were recorded.
A note on Brythonic last names: As with their Viking counterparts, most Brythons would have a given name and then either a list of their fathers using the word 'ap' to mean 'son of' (i.e Llewelyn ap Cyny ap Rhodri) or a suffix with some sort of descriptor (i.e Rhodri Mawr 'The Mighty').
Welsh Names
Taken largely from the Book of Llandav. Please note this list is not exhaustive.
Aedan/Aidan - Aerthirn {Eudeyrn} - Aircol {Aergul} - Arhuiret - Arthbodu/Arthuodu {Arthfoddw} - Arthcumanu - Arthmail {Arthfael} - Athruis - Atoc - Auner - Beli - Biuan/Biuon - Bledgur - Bledri {Bleddri} - Bledud {Blaiddudd} - Bleidcu {Bleiddgu} - Bleinbiv - Brachanios (d)? {Brychain} - Branud - Briauail {Briafael} - Brochmail/Brochuail/Brocuail/Brochmaili (g) {Brochfael} - Byrguith - Caratauc {Caradog} - Carbani (g) - Catell {Cadell} - Catgen - Catgual {Cadwal} - Catguallaun {Cadwallon} - Catguare/Catguaret/Catguoret {Cadwared} - Catgucaun/Catguocaun/Catgucauni (g) {Cadwgon} - Catleu - Catoci (g) {Cadog} - Ceitimor - Cerenhir/Cerennhir - Cetuur - Cidrich/Cydrich {Cydrych} - Cilciuhinn - Cimeilliauc - Cinan/Cinon/Conan - Cinbran/Conbran/Cunbran {Cynfran} - Cincenn/Concen {Cyngen} - Cingual/Cinguali (g) {Cynwal} - Cingualan {Cynwallon} - Cinnhor/Cinnor - Cinuchan - Cinuedu - Cinuin - Cinuoc - Citoc - Ciuarheru - Cobreigen - Coilbrit/Colbrit - Conbrinun - Condaf {Cyndaf} - Confur/Conuur {Cynfer} - Congen - Conguare - Conguean - Congurique {Cynwrig} - Conhail - Conhibrit - Conlec - Conoc - Conuan - Conueon - Conuetu/Conuoet - Conuoge - Conuonuc - Cors - Crashaiou - Cuchein - Cuelino {Cuhelyn} - Cunuaret {Cynwared} - Cunueon - Cyngualan {Cynwallon} - Cyngur - Dibin - Dissaith - Diuaret - Diuin - Docunni (g) - Dofngarth - Dofran - Draincun - Dubricii (g)/Dubricio {Dyfrig} - Duna/Dunna - Ebba - Eidef - Eidniuet {Ednyfed} - Einbresel - Eithin - Elci/Elcu - Elfin - Elgued - Eli - Elinui {Elinwy} - Elisael - Elised {Elisedd} - Elstan - Enim - Enniaun {Einion} - Erbic - Esne - Eudeat - Euilaun - Eutigirn {Eudeyrn} - Frioc - Gabran - Gallcun - Gallun - Garu - Gellan - Gendoc/Gindoc - Gistin/Gistinus - Gistlerth/Gistrerth - Gleinguid - Gliuis {Glywys} - Gloiu - Grifud/Grifudi (g) {Gruffudd} - Grucinan - Guabeith - Guaidnerth {Gwaeddnerth} - Guainint - Guallonir/Gullonar - Gucaunus/Gucauno (d) - Guebric - Guedgen/Guedguen/Gueithgen?/Guidgen/Guidgen(-)tiuai {Gwyddien} - Gueiluirth - Gueithgno - Guelbiu - Guencat - Guengarth - Guerngen - Guidlovius/Guodloiu - Guidnerth {Gwyddnerth} - Guinan - Guingual/Guingualum - Guithrit - Gulbrit - Gunbiu - Guncar - Gunda - Guocob/Guocof - Guonocatui - Guordic - Gurcano (d)/Gurcant/Gurcanti (g) {Gwrgant} - Gurceneu/Gurceniu/Gurcenou {Gwrgeneu} - Gurci {Gwrgi} - Gurcimanu (This person is the father of the Gurci listed. Does this possibly show a tradition of choosing children's names that share an element with the parent's?) - Gurcinnif - Gurcon {Gwrgon} - Gurdilic {Gwrddylig} - Gurdocui {Gwrddogwy} - Gurguistil {Gwrwystl} - Gurhaval - Guriat {Gwriad} - Guronui {Gwronwy} - Gustin - Haiuoen - Heufric - Higueid/Huweyn/Ouein/Yugein {Owein} - Hirel - Hiuel/Hiugel/Houel/Huwel {Hywel} - Idcant - Idguallaun/Iudguallaun/Iudguallon {Idwallon} - Idguin - Idmab - Idnerth {Idnerth} - Ilud {Illud} - Ismael {Isfael} - Ithail/Iuthel/Iudhail/Judhail {Ithel} - Iudcant - Iudgual {Idwal} - Iudguoret {Idwared} - Iudhubr - Iudic {Iddig} - Iunet - Iurthir - Jouaf - Laur - Letric - Libiau/Libiauo (d) - Lifris - Loudoce - Louheithi/Luuaet - Loumarch/Luuarch {Llywarch} - Lugobi (g) - Mailbrigit - Maioc/Maiuc - Malcant - March/Marchi (g) - Margetud {Maredudd} - Matauc/Matuc {Madog} - Mei - Merchbiu/Merchuiu {Merchfyw} - Merchguinus/Merchuino (d) {Merchwyn} - Merchiaun {Merchion} - Merchitir - Merthyr - Milgen - Mor - Morcan/Morcant/Morgan - Morcenou {Morgeneu} - Mormarch/Moruarch {Morfarch} - Mouric/Mourici (g)/Mouricus/Muricus {Meurig} - Nir - Nouis - Nougui {Nowy} - Nud {Nudd} - Oguhyr - Oran - Oudoceus {Euddogwy} - Reu - Riacat - Richrit - Riderch {Rhydderch} - Riguallaun/Riuallaun/Riuguallaun {Rhywallon} - Rihedl/Rihoithil/Rioidyl - Ris {Rhys} - Riuelgur - Rotri {Rhodri} - Ruid - Run {Rhun} - Sadoc/Satuc - Scituc - Sed - Sulgen {Sulien} - Tecguaret {Tegwared} - Teudiric {Tudwrig} - Teudur {Tudur} - Teudus {Tudws} - Tirchanus/Trichani (g)/Trycan/Trychan - Titgual {Tidwal} - Turguert - Tutnerth {Tudnerth} - Ubeluiuo -
Cornish Names
The Brythonic inhabitants of Devon and Cornwall would have been very similar to their cousins in Wales, but more influenced by their relatives in Brittanny and an influx of raiders and settlers from Ireland. In some sources 'ap' is changed to 'ab' in a Cornish context.
Names taken largely from the Bodmin Manumissions. List is not exhaustive.
Aedan - Anaoc - Aniud - Argantbri - Argantmoet - Beli - Bledros - Bleidiud - Brenci - Brethoc - Brithael - Budic - Cantgueithen - Catgutic - Cenmin - Cingur - Cinhoedl - Comoere - Conmonoc - Conredeu - Dengel - Dofagan - Duihon - Frioc - Gest - Gratcant - Grifiud - Guentanet - Guentigirn - Guincum - Guithrit - Gurbodu - Gurcant - Gurcencor - Gurci - Gurcon - Gurdilic - Gurguaret - Gurguistl - Gurheter - Guriant - Gurlouen - Hedyn - Hincomhal - Iarnguallon - Ilcarthon - Iliud - Inisian - Iudicael - Iudnerth - Leucum - Loi - Louenan - Loumarch - Maeloc - MaelPatraic - March - Matuid - Medrod - Mermin - Mor - Morcant - Morhaetho - Ossine - Patrock - Piran - Putrael - Resmen - Rinduran - Riol - Ryd - Talan - Telent - Terithien - Tethion - Ungust -
Breton Names
Britanny was founded just prior to our period by Brythonic people fleeing Saxon expansion and founding colonies on the northern shore of what had once been Roman Gaul. The name of the duchy still reflects this heritage and Breton and Cornish remained mutually intelligible into the medieval period.
Taken largely from Davies, Wendy et al. 2000. The Inscriptions of Early Medieval Brittany. Celtic Studies Publications, Oakville.
Adiuni - Bodognous - Belado - Britou - Budnouenus - Conbriti - Disideri - Felix - Gallmau - Gennovevs - Heranal - Harenbili - Iocilin - Iusti - Lagu - Maeldoi - Maonirn - Mihael - Riocus - Turtoualdus - Uenomaili - Vormvini -