To Honor by Cecelia Mecca

In the midst of England’s bloody civil war, a forbidden love threatens to destroy reputations and reshape destinies.

When celebrated tourney champion Sir Gareth joins a secret knightly order, he falls for the daughter of a powerful baron. Sir Gareth would be the perfect match for Lady Evelina . . . if he weren’t the disgraced son of an accused traitor.
Sir Gareth and Lady Evelina are drawn together by passion neither can deny. As their clandestine affair ignites desires that could ruin them both, Gareth hatches a bold plan. He will embark on a death-defying mission behind enemy lines to prove his worth to the baron once and for all.
Surrounded by enemies, with scandalous ruin looming, Gareth fights for his honor, his country, and the heart of the woman he loves. Can the celebrated knight secure redemption and claim Lady Evelina as his bride? Or will their forbidden love doom them to heartbreak and tragedy?