The article discusses Welsh national identity in the nineteenth century, an identity of which religion was an important aspect. Firstly, the article summarises the history of Christianity in the Principality from Roman times to the Reformation and the adoption of Anglicanism until the nineteenth century. It was during this century that an increasing number of people rejected the established Anglican Church in favour of non-Anglican Protestant churches (known as Non-Conformist churches). In light of these developments, issues discussed in the article include the attitude of the Welsh to England and the Church of England, the attitude towards Catholic Ireland and the impact of non-conformism on Welsh politics, education, and the literary and musical traditions. Taken together, these lead to a discussion on the influence of Non-Conformity on Welsh patriotism.