Saint Eigen was an early Christian writer and legendary figure among the Britons. While her historical existence is considered uncertain due to limited evidence, she is often identified as a possible first female saint of the Britons. Some traditions link her to the daughter of Caratacus, suggesting she lived around the end of the first century. Various manuscripts, including those from the collection of Iolo Morganwg, associate her with the introduction of Christianity to the Welsh people through a religious group known as Cor Eurgain.