The Brothers of Ash & Fire: Box Set by Lauren Smith

They are the last of the last of a powerful but vanishing dragonshifter bloodline…

Mikhail:
Mikhail Barinov knew he F’d up, five hundred years ago. His ‘one job’ as part of a Russian family of imperial dragon shifters? To protect the family hoard of jewels. But a dazzling virgin—who just happened to be the Elizabeth I, the Queen of England—tricked Mikhail and stole the jewels. But now he has a chance at redemption. The jewels have been found five centuries later. The only problem is they’ve been turned over to gemologist, Piper Linwood. She’s sexy, smart, ripe for seduction—but if centuries of exile taught him one thing, it’s never trust a beautiful woman.

Rurik:
The fiercest of a royal line of Russian dragon shifters, Rurik Barinov spends most days defending his family’s homeland from rival clans. By night, sins of the flesh—drinking, dancing, and sex—keep his volatile warrior dragon in check. Barely.
With his choice of mortal women to bed, he has no interest in changing his bad-boy ways—until a creature of molten sex poured into a tiny red satin dress steps into his nightclub. And a jagged edge of raw desire nicks the impenetrable armor around his heart.
Charlotte MacQueen has been told since childhood to stay in school, live a normal life. Leave the family business—hunting down dragons—to her brothers. But tonight, she’s shed her chemist’s lab coat and infiltrated enemy lines to bag a dragon of her own.