Tower of the king's daughter - Chaz Brenchley

Set in the Kingdom of Outremer, TOWER OF THE KING'S DAUGHTER draws upon rich veins of history, religion and politics, bringing a powerful and imaginative new voice to fantasy fiction.
Forty years on from the establishment of the Outremer, trouble is stirring. The religious, determined to root out heresies within the kingdom, have made a base in their stronghold of Roq de Rancon, protected by the Knight Ransomers.
And in this remote and secretive place, a tale of love, duty and betrayal will unfold: for Marron, a young man newly sworn to the Ransomers; for Julianne, daughter of the
King's Shadow, en route to her wedding in Elessi; and for Elisande, her young and mysterious companion. All have a part to play in the coming upheaval, for their lives are intricately involved with the fate of the kingdom . . .