I do not read historical romance but I looked some places if you want to dig some as a head start...
MEDIEVEL
The Mer-Lion by Lee Arthur
Lion's Heart (Harlequin Historical) by Suzanne Barclay Lion Of The North (Harlequin Historical) by Suzanne Barclay Lion'S Legacy (Harlequin Historical) by Suzanne Barclay Lion'S Lady (The Sutherland Series) (Historical) by Suzanne Barclay Pride Of Lions (Mills & Boon Vintage 90s Historical) by Suzanne Barclay Taming the Lion (Harlequin Historical) by Suzanne Barclay
Lion Heart (Avon Romantic Treasures) by Tanya Anne Crosby
The Lion In Glory (Zebra Historical Romance) by Shannon Drake
Lion Of Mortimer by Juliet Dymoke
Lion Of Trevarrock by Constance Fecher
Heart of a Lion by Hillary Fields
A Memory Of Lions by Parke Godwin
Lion's Bride by Iris Johansen
Shield of Three Lions: A Novel by Pamela Kaufman
Lion of Ireland (Celtic World of Morgan Llywelyn) by Morgan Llywelyn Pride of Lions by Morgan Llywelyn
The Lion's Bride by Connie Mason
Heart of the Lion by Jean Plaidy The Lion of Justice (The Second Book of the Norman Trilogy) by Jean Plaidy
MEDIEVEL
The Mer-Lion by Lee Arthur
Lion's Heart (Harlequin Historical) by Suzanne Barclay
Lion Of The North (Harlequin Historical) by Suzanne Barclay
Lion'S Legacy (Harlequin Historical) by Suzanne Barclay
Lion'S Lady (The Sutherland Series) (Historical) by Suzanne Barclay
Pride Of Lions (Mills & Boon Vintage 90s Historical) by Suzanne Barclay
Taming the Lion (Harlequin Historical) by Suzanne Barclay
Lion Heart (Avon Romantic Treasures) by Tanya Anne Crosby
The Lion In Glory (Zebra Historical Romance) by Shannon Drake
Lion Of Mortimer by Juliet Dymoke
Lion Of Trevarrock by Constance Fecher
Heart of a Lion by Hillary Fields
A Memory Of Lions by Parke Godwin
Lion's Bride by Iris Johansen
Shield of Three Lions: A Novel by Pamela Kaufman
Lion of Ireland (Celtic World of Morgan Llywelyn) by Morgan Llywelyn
Pride of Lions by Morgan Llywelyn
The Lion's Bride by Connie Mason
Heart of the Lion by Jean Plaidy
The Lion of Justice (The Second Book of the Norman Trilogy) by Jean Plaidy