The migration of Flemings to the cantref of Rhos is recorded by Giraldus Cambrensis, `Descriptio Kambriae', in Opera VI, ed. J.F. Dimock, Rolls Series (1868), 82-3, and in The chronicle of John of Worcester III, ed. and trans. P. McGurk (Oxford, 1998), 124-7, but nothing is said in either of the flooding of their homeland.