First published in 1968, The Dragon Has Two Tongues was the first book-length study of the English-language literature of Wales. Glyn Jones (1905–95) was one of Wales's major English-language writers of fiction and poetry, and the book includes chapters dealing with the work of Dylan Thomas, Caradoc Evans, Jack Jones, Gwyn Thomas and Idris Davies, all of whom the author knew personally.

This first-hand knowledge of the writers, coupled with the shrewdness of Glyn Jones's critical comments, established The Dragon Has Two Tongues as a classic and invaluable study of this generation of Welsh writers. It also contains Glyn Jones's own autobiographical reflections on his life and literary career, his loss and rediscovery of the Welsh language, and the cultural shifts that resulted in the emergence of a distinctive English-language literature in Wales in the early decades of the twentieth century.

This edition of The Dragon Has Two Tongues was edited by Tony Brown, who discussed the book with Glyn Jones before his death in 1995 with unique access to the author's proposed revisions and manuscript drafts, and it was first published by the University of Wales Press in 2001.