Saint Patrick, whose feast day is celebrated on 17 March, left behind two short works in Latin, but he probably spoke a Celtic language. By the time he was saving Irish souls in the fifth century AD, linguists are pretty sure that Celtic was spoken throughout Britain and Ireland. When Celtic first arrived in those islands, however, is an enduring mystery – one that new findings in archaeology and genetics might help to solve.
The dates range between the early bronze age, around 2500BC, when archaeologists detect a major cultural transformation in Britain and Ireland, and the first century AD. Most linguists place it in between, in the last millennium BC – the iron age – but they can’t prove it because the language wasn’t written down until much later.
