What is Brythonic? Is it Britain’s native language? Ancient Celtic tongue explained

Before the Roman invasion, most inhabitants of the British Isles were said to speak the ancestral language Brythonic (Brittonic) which modern Celtic languages can be traced back to.

English is the dominant tongue of society today, but historically this is relatively new. In Scotland, for example, Germanic languages like Scots Leid were not always the ‘lingua franca’ of the land but rather Celtic languages were.

For most, this brings Scottish Gaelic to mind. The endangered heritage language has been popularised with Gaelic phrases in Outlander and learning courses on Duolingo (traces of it even appear in modern place names.)

However, Gaelic is an offshoot of a much deeper Celtic linguistic heritage that spans not only the land we know as Scotland or Britain but even the European continent. When discussing a Celtic tongue of the British Isles, a commonly heard ‘quip’ is “that’s not our native language, Brythonic is.”

Irish, Gaelic, Manx, Cornish, Breton and Welsh are all Celtic languages of the British Isles still surviving today (some barely) but can they truly all be attributed to Brythonic? Here’s an overview of what Brythonic is, when it was spoken, and if it is truly Britain’s ‘native’ language.

Many academics assert that the Picts spoke a Celtic language that was connected to Brythonic. However, we'll likely never know for sure as there are no provable records.

What is Brythonic?

Oxford Languages tells us that Brythonic is “the southern group of Celtic languages, consisting of Welsh, Cornish, and Breton.” These ‘Britonnic languages’ form one of two major branches of the existing Celtic language family; the other is the Goidelic branch which accounts for Gaelic.

Welsh Celticist John Rhys coined the term in 1879 as he derived it from the Welsh word ‘Brython’ which denotes an ancient Briton. When people refer to Britain’s native language as ‘Brythonic’ it is likely they mean to refer to ‘Common Brittonic’ which is the ancient Celtic tongue that by the sixth century began diverging into its offshoots.

Emigrants of the British Isles took Common Brittonic with them to the European continent in regions like Brittany (France) where the ‘Neo-Brittonic’ language Breton is still spoken today.

This combined flag of the Celtic nations represents Irish, Scottish Gaelic, Manx, Welsh, Cornish and Breton (which is an extant language of the Brythonic group.)

How old is Brythonic?

Common Brittonic (also known as Proto-Brythonic) is said to have been spoken from around the 6th Century BC to the 6th Century AD across the majority of Britain i.e., it was used during the Iron Age and Roman period.

Many scholars suspect that the Picts, ancient Celts whose presence can still be felt by way of Pictish stones scattered throughout Scotland, had a language derived from Common Brittonic. Sadly, as an extinct culture the ‘Pictish’ tongue remains a mystery to scholars.

By the sixth century in Scotland, Old English (in the south and east) and Gaelic speakers (in the north and west) replaced Common Brittonic.

"Brittonicisms" are linguistic effects in English attributed to the historical influence of the Brittonic language; they're particularly prominent in the names of British rivers.

Is Brythonic the native Celtic language of Britain?

Historians have dated the arrival of the Celtic tongue in Britain to at least two and a half thousand years ago (some argue even earlier.) As written in ‘The Atlantic Iron Age’, this original Celtic language or ‘Proto-Celtic’ is the supposed parent language which gave rise to Proto-Brythonic and the Brittonic offshoots that emerged from that.

Etymologists uncovered that early European languages influenced the Celtic language family as we understand it today, and those influences had common heritage with a language broadly dubbed ‘Indo-European’.

Indo-European developed into multiple language groups, including Celtic, which we know existed in Europe with Gaulish in France and northern Italy, Galatian in Turkey and Celtiberian in Spain.

The Celtic languages that migrated from the continent of Europe to the British Isles are those that survived long enough in order to become the Brittonic and Goidelic tongues still spoken.

Ultimately, as the University of Wales reports, “Celticity has historically been a chronically vague and indefinable concept” and this can apply to efforts to explain the origins of Celtic languages in Britain.

Parent tongues of today’s languages descend from countless other languages lost to time. Thus, in the wake of global anglicisation i.e., English-speaking dominance in society, it seems prudent to focus on the preservation of Celtic languages lest they become yet more linguistic relics lost to time.