To define Romanticism with precision has proved impossible - because it is a movement, a phase in human consciousness; but those who feel it will recognise it when we see it.
To be included in this list, one must be both Romantic and Christian (and be someone whose work I personally respond-to):
William Blake
William Wordsworth
ST Coleridge
Then came several generations during which the Romantics were not Christian, and the Christians were not Romantic. Exceptions include George Macdonald and GK Chesterton, who link between the early Romantic Christians and the Inklings. Both of these I somewhat like, especially GKC - but I am unable to engage whole-heartedly.
Charles Williams
JRR Tolkien
CS Lewis
Owen Barfield
William Arkle
Current representatives of whom I am aware include Jeremy Naydler, Terry Boardman, and the Albion Awakening bloggers: William Wildblood, John Fitzgerald and myself.
Comments:
The influence of Rudolf Steiner is evident; since although Anthroposophists are extremely rare in England - Barfield, Naydler and Boardman are all of that ilk. This is evidence that Romanticism fits most comfortably with heterodox Christianity - despite that Tolkien (Roman Catholic) and Lewis (Church of England) were orthodox in their practice. Indeed; Blake, Barfield (for much of his life), Arkle and most of the currently alive people - are (I believe) essentially unaffiliated Christians; whose religious and spiritual practice is mostly and in-principle individual rather than communal.
The Steiner link is also important because Germany (in the sense of the Central European German-speaking culture - including Austria and Switzerland, and some culturally-Germanic cities not nowadays in Germany) was the other great origin of Romanticism - with Herder, Goethe, Schiller etc. However until Steiner's 'conversion' in about 1898; the German Romantic literary tradition was not really Christian. An exception is Novalis - the father of Romantic Christianity in Germany.
It might also be argued that CG Jung (1875-1961) is also part of the German tradition of Romantic Christianity - although (as so often with Jung) his status as a Christian is ambiguous - overall, I would say that by the end of his life, Jung should indeed be regarded as a Christian.
There are not many on this list; because I don't know of many Romantic Christians. It is a job still to be done, by each individual - since Romantic Christianity must be experiential (knowing 'about' it does not suffice).
However, I regard both Barfield and Arkle as having essentially done the necessary work and, uniquely, achieved Romantic Christianity: both in their theory and in their living.
Mainstream Christianity still tends to regard Traditionalism as a 'safe' path to salvation; and theosis as too 'risky' - and Romanticism is about theosis.
But for the Romantic Christian there is no 'safe' path in the modern world; and traditionalism has in fact become impossible (judged at the deepest level of motivation); as well as sub-optimally desirable. We feel that, in modern conditions, salvation requires theosis; so a purely salvation orientation can only be a kind of 'rescue' procedure.
Because ultimately Romanticism is not a 'reaction' against the Industrial Revolution, modernity and bureaucracy; rather, Romanticism is a positive path of divine destiny, concerned with human evolutionary-development of consciousness.
The aim of Romantic Christianity is (implicitly) to attain the divine form of cosnciousness (what Barfield termed Final Participation) as the primary goal of mortal life at this era of history. In different words: the aim is to restore the unity of Life - including the healing of the split between mind and matter, subjective and objective... to cure the malaise of alienation.
Romantic Christianity is both theoretical (metaphysical) and practical (experiential) - ideas and living both need to change; because otherwise the two aspects will be at contradictory, at war - and therefore unattainable in life.
The Romantic Christian demands that life be Christian - as its root and frame; and also demands that life (including Christianity) be Romantic - therefore it cannot accept the ultimate of primary necessity of System, organisation, institution, bureaucracy... these are all to be regarded as evils; even if, sometimes (in mortal life); expedient or even temoprarily-necessary evils - evils that challenge us to love, faith and hope; and to grow.
Love and creativity are the goal; with creativity as located in thinking, and thinking regarded as universal and primary.