高肇
Yuan Xu was born in 510. He was the only son of Emperor Xuanwu to be alive at that point. (Emperor Xuanwu had other sons before him, but each died in infancy or childhood, and only one of them, Yuan Chang (), the son of Emperor Xuanwu's first wife Empress Yu, is known to historians by name.) Yuan Xu's mother was Emperor Xuanwu's concubine Consort Hu. As the only male offspring of Emperor Xuanwu, Yuan Xu obtained much of his father's attention: Emperor Xuanwu selected several experienced mothers to be Yuan Xu's wet nurses, forbidding his second wife Empress Gao and Consort Hu to be near him, perhaps because popular opinion at the time believed Yuan Chang to have been murdered by Empress Gao's (and Emperor Xuanwu's) uncle, Gao Zhao.