The Vendetti Empire: Capo dei Capi by Sapphire Knight

They’re the Vendetti crime familia, the most powerful mafia name in New York…
Matteo Vendetti is a man who gets what he wants. As heir to the Vendetti Empire and the capo dei capi’s throne, he’s only required to do one thing. He must get married to prove that he’s matured and is stable enough to take over. The stipulation doesn’t sound like much of a challenge until he realizes who his betrothed is. Violet’s the Bottaro Princessa, not just a random woman he met by chance in another country. She’s young—too young by his standards. She’s headstrong—a problem for a dominant man like Matteo. She’s desirable—the biggest issue of all.
Before long, Matteo’s questioning himself, wondering if Violet’s really such a burden, or if just maybe, he’s falling in love with something other than the Empire.