Waiit what's the backstory of Lord Sigmund and Romia again???

Lord Sigmund meet Romia a traveler if I remember who was apart of Genos Kingdom and taught him the value of humans in return with time he fell in love with her and married her. Since she was a human with human life span she died of old age and lord Sigmund loved her to the end and promised to protect her kingdom, Genos because he came to vaule humans the way she does. I think there's a bit more but that's all I remember