The Queen Maker - Royal Blood, #2

Raised the daughter of an indentured servant, Thana Leoram has brought King Keiran Sipesh to his knees. The vampire is willing to break the law to pursue their forbidden love, and she is ready to submit to her desires. Before they get the chance, though, word of an invasion by the Sador Empire arrives. The young and untested king marches off to war, leaving Thana behind. However, Thana's mother will do anything to stop her daughter's relationship with the vampire, and with him gone, a plan is put into motion that will force Thana from the castle in fear for her life. Not knowing who else to trust, Thana flees to find Keiran, following him into the fray.
Though she only sought sanctuary, she becomes the central prize of the war itself. A Sadori general realizes Thana is far more precious than Tordania's coal. She will offer him a route to glory, and the painful truth of her very existence will be laid bare. She will have to choose between a life of luxury in the hands of her Sadori captors, or risk her life in an escape to return to the vampire she loves.