Who is General Xue from Wild Swans: Three Daughters of China and what is their importance?

General Xue is an important military leader. Yu-Fang's father arranges for the general to see Yu-Fang, hoping he'll be taken by her beauty. He is and he soon offers to take her as a concubine, paying Yu-Fang handsomely for her. He lives in Lulong, but arranges a house for Yu-Fang in Yixian. His wife and other concubines live in Lulong and Yu-Fang is privileged to be saved from the bickering of that type of household. He stays with Yu-Fang briefly after their "marriage" and then leaves, staying away for six years.