The Iron Princess (Sons of the North #2)
Sandra Lake

The daughter of a Northern warlord, Katia is known as the Iron Princess for her mettle in battle. Headstrong and defiant, she instigates sword duels on a whim with little regard for her own safety. Katia would rather die on her feet as a warrior than live as a token wife and child bearer for a husband who keeps her castled as if she were a prisoner.
Lothair is the illegitimate son of the Duke of Saxony, who was granted the title of baron, a castle and lands. Raised in an atmosphere of mistrust and deceit, he rejects the concept of husbandry and wants a life of purpose and sacrifice in the pursuit of security for the Baltic Sea.
And when fate brings the Iron Princess and reluctant baron together, Katia and Lothair discover they are kindred spirits with fiery temperaments—and insatiable desires—to match…