"Lann" in Breton, and "Ilann" in Welsh, are two similar words, meaning a monastery, or a retreat in the 6th century, when Telo is said to have come to Brittany from Britain. It was between the 4th and 8th centuries that a massive number of Bretons came from Britain across the Channel to live in Brittany.

Telo is still celebrated in Landeleau, in the Finistere. Every Whitsunday, people go on a procession, which is one of the oldest rituals in Brittany. People gather together and walk around the parish, carrying what is believed to be the relics of Telo. His story has now become part of the Welsh heritage, despite being forgotten after the Protestant Reformation in the 16th century.

This documentary covers the life of Telo, looking for proof of his life and travels through Wales and Brittany. In place-names, for instance, as in a lifestory written in Latin in the 12th century, or an 8th century gospel.

Ronan Hirrien shows us how over 15 centuries Brittany and Wales have regularly moved closer together and been torn apart.