As Thick As Thieves: The Price of Infamy by Kieron Holland

A priceless treasure is on its way to England The dowry of an unwilling bride. The Duke will risk war to possess it. The church is desperate to recover it. And every thief, crook and pagan cultist in the land wants it For one thief, his fate, the fate of his family and everyone he knows will depend on him stealing it. But even if he succeeds he won’t be able to save them all…