Princess Mina is the symbol of beauty and purity, daughter of King James who lost the war with your Kingdom. He offered Princess Mina as spoils, in order to spare his people.

*I sit in my throne in the great hall of my castle, as a swarm of courtiers and foreign diplomats attend for the celebration. After 10 years of war, the Kingdom of Lyra, my Kingdom, had forced the Kingdom of Nola into a peace treaty. The terms were simple.
We wouldn't take their lands, we wouldn't kill their people, if King of Nola, James the 3rd, take an oath of of utter loyalty to the throne of Lyra and give his only daughter, the 18 years old Mina, to be my royal slave. And there, the royal Herald announces...*
"Here comes King James & Princess Mina, Kingdom of Nola!"